SlideShare a Scribd company logo
1 of 6
Download to read offline
Chapter 32
Post-term Pregnancy
                                                                                 Jamie L. Resnik, MD, and Robert Resnik, MD




In 1902, Ballantyne1 described the problem of the post-term pregnancy        screening examination performed between 17 and 22 weeksā€™ gestation
for the ļ¬rst time in modern obstetric terms. Although the language           was reported in one recent study to be more accurate in predicting the
used to describe the entity in early 20th-century Scotland was different     delivery date than a ļ¬rst-trimester screen,5 most reports have tended
from that of today, Ballantyneā€™s words clearly reļ¬‚ected the thinking of      to agree with the ļ¬ndings of Bennett and associates.6 These authors
his time: ā€œThe postmature infant . . . has stayed too long in intrauterine   randomly assigned women to either a ļ¬rst-trimester (n = 104) or a
surroundings; he has remained so long in utero that his difļ¬culty is         second-trimester (n = 92) ultrasound examination; 5 of the women in
to be born with safety to himself and his mother. The problem of             the ļ¬rst group underwent labor induction for a post-term gestation,
the . . . postmature infant is intranatal.ā€                                  compared with 12 of those in the second group. In any case, it is clear
    During the ensuing years, the issue of post-term pregnancy, its          that use of the LMP alone tends to substantially overestimate the
risks, and its management generated great interest and controversy. An       number of post-term gestations and that the widespread use of ļ¬rst-
abundance of older as well as more recent data have ļ¬rmly established        trimester ultrasound examinations, now used for noninvasive genetic
that the fetal risk associated with a prolonged pregnancy is real, albeit    screening, will have a great impact on the diagnosis and subsequent
small. Consequently, the pregnancy that continues beyond 42 weeks            management of this entity.
requires careful surveillance.

                                                                             Pathogenesis
Deļ¬nition and Incidence                                                      Knowledge of the mechanism of parturition is increasing rapidly, and
By deļ¬nition, a term gestation is one that is completed in 37 to 42          the current understanding of the pertinent molecular, biochemical,
weeks. Pregnancy is considered prolonged, or post-term, when it              and physiologic ļ¬ndings are reviewed in Chapter 5. It is clear that the
exceeds 294 days from the last menstrual period (LMP), or 42 weeks.          normal timing of parturition requires the integration and synchrony
The frequency of this occurrence has been reported to range from 4%          of numerous factors, including the fetal hypothalamic-pituitary-
to 14%, with only 2% to 7% of pregnancies completing 43 weeks. The           adrenal axis, the placenta and its membranes, and the myometrium
chances that parturition will occur precisely at 280 days after the ļ¬rst     and cervix. Although it is not known speciļ¬cally why some pregnancies
day of the LMP (40 weeks) is only 5%.                                        are abnormally prolonged, clues exist from interesting observations of
    One of the major problems in delineating the extent of risk beyond       aberrant timing of labor in humans and other species. For example,
term is the limited reliability of the LMP as a basis for accurately pre-    it has long been known that fetal pituitary defects in Holstein cattle
dicting gestational age. Traditionally, and until the 1990s, most epide-     may lead to failure of normal delivery timing.7 In humans, congenital
miologic studies pertaining to fetal and neonatal risks of delayed           primary fetal adrenal hypoplasia and placental sulfatase deļ¬ciency
parturition were based on the LMP. Since that time, the use of ultra-        leading to low estrogen production may result in delayed onset of labor
sound, particularly in the ļ¬rst trimester, has led to much greater preci-    and failure of normal cervical ripening.8,9
sion in pregnancy dating, and data conļ¬rm that the LMP is a much                 Whether the primary defect in delayed parturition involves aberra-
less reliable predictor of true gestational age. For example, as early as    tions in fetal endocrine signaling or abnormalities in the setting of the
1988, Boyd and colleagues2 showed that the incidence of post-term            ā€œplacental clockā€ (as was suggested by McLean and colleagues10), or
gestation fell from 7.5% when based on menstrual dating to 2.6%              whether the myometrial contractile and cervical softening mechanisms
when early ultrasound examination was used. In a subsequent study            are at fault, it is clear from the abundant data currently available that
by Gardosi and colleagues,3 the post-term delivery rate among women          the timing of parturition is determined by complex interactions at the
dated by LMP was 9.5% but decreased to 1.5% if ultrasound dating             maternal-fetal interface.
was used. In their study, 71.5% of ā€œpost-termā€ inductions as dated by
LMP were not post-term according to ultrasound studies. This ļ¬nding
is consistent with the observations of Taipale and Hiilesmaa,4 who
performed ultrasound examinations at 8 to 16 weeksā€™ gestation in
                                                                             Risk Factors
17,221 women. When ultrasound biometric criteria rather than the             Primiparity has long been known to be more frequently associated
LMP were used to determine gestational age, the number of post-term          with post-term gestation than multiparity. However, there also appears
pregnancies fell from 10.3% to 2.7%. Although a second-trimester             to be an increased frequency of recurrence among women who have
614      CHAPTER 32             Post-term Pregnancy

had a previous post-term pregnancy. One large cohort study from
                                                                                                                      6
Denmark has demonstrated that women who delivered post-term in
                                                                                                                               Stillbirth
their ļ¬rst pregnancy had an almost threefold increase in the incidence
                                                                                                                               Neonatal death
of subsequent post-term pregnancy, compared with those whose ļ¬rst                                                              Postneonatal death
delivery was at term.11 These ļ¬ndings were recently conļ¬rmed by                                                       5
Kistka and coworkers12 in a study of 368,633 births in Missouri, in




                                                                             Mortality per 1000 ongoing pregnancies
which mothers with an initial post-term birth were at increased risk
for a subsequent post-term pregnancy (relative risk [RR], 1.88; 95%
conļ¬dence interval [CI], 1.79 to 1.97). These ļ¬ndings also suggest the                                                4
possibility of a genetic predisposition, inasmuch as the risk of recur-
rent post-term pregnancy in the Danish study was not observed if the
ļ¬rst and second children had different fathers.
                                                                                                                      3



Perinatal Risks                                                                                                       2

Morbidity and Mortality
Almost all reports up to the present time, even those with inherent
limitations imposed by inaccuracies in gestational age determination,                                                 1
suggest an increase in perinatal morbidity and mortality when preg-
nancy goes beyond 42 weeksā€™ gestation. One of the earliest and most
frequently cited studies was provided by the National Birthday Trust                                                  0
of Britain in 1958, which undertook a detailed examination of more                                                     28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
than 17,000 births in the United Kingdom from March 3 to March 9                                                                      Gestational age (weeks)
of that year.13 Their data demonstrated that the perinatal mortality rate
began to increase after 42 weeksā€™ gestation, doubling by about 43 weeks,    FIGURE 32-1 Perinatal mortality as a function of gestational age.
and was four to six times higher at 44 weeks than at term. A more           The rates of stillbirth, neonatal, and postneonatal death increase with
                                                                            advancing gestational age beyond 41 weeks. The perinatal mortality
recent study showed that the risks begin to accelerate between 41 and
                                                                            is expressed per 1000 ongoing pregnancies. (From Hilder L, Costeloe
42 weeks and rise more sharply after that point (Fig. 32-1).14 Numerous     K, Thilaganathan B: Prolonged pregnancy: Evaluating gestation-
other reports have conļ¬rmed this increase in risk.15-17 Alexander and       speciļ¬c risks of fetal and infant mortality. BJOG 1998;105:169-173.)
associates18 retrospectively evaluated outcomes of more than 27,000
pregnancies with 41 or 42 weeksā€™ gestation, compared with approxi-
mately 29,000 completed at 40 weeksā€™ gestation. Length of labor, inci-
dence of prolonged second-stage labor, forceps use, and cesarean            pared with term infants,17,23 and birth injuries can occur as a result of
delivery were all increased with the longer gestation period. It is not     difļ¬cult forceps deliveries and shoulder dystocia. Morbidity also
clear, however, whether the observed increase in complications was due      includes cephalohematomas, fractures, and brachial plexus palsy.24
to prolonged gestation, routine use of induction at 42 weeks, or            Study of fetal growth characteristics in 7000 post-term infants con-
both.                                                                       ļ¬rmed a gradual shift toward higher birth weights and greater head
    In a more recent Norwegian study, in which 17,493 pregnancies           circumference between 273 and 300 days of gestational age.25 These
with conļ¬rmed dates by second-trimester ultrasound were analyzed,           ļ¬ndings were further reinforced by a study of 519 pregnancies extend-
1336 were found to be post-term. The post-term group had twice the          ing beyond 41 weeks, in which 23% of the newborns weighed more
perinatal mortality rate (CI, 0.9 to 4.6); the RR of having an Apgar        than 4000 g and 4% weighed more than 4500 g.26
score lower than 7 at 5 minutes was 2.0 (CI, 1.2 to 3.3), and the RR of         Although the majority of post-term infants are appropriately grown
requiring neonatal intensive care was 1.6 (CI, 1.3 to 2.0).19 Another       or macrosomic, the risk of a small-for-gestational-age (SGA) infant is
prospective cohort study of 27,514 pregnancies from the same country        also increased in post-term pregnancy. In a population-based study of
demonstrated that maternal and fetal risks were lowest at 39 weeksā€™         510,029 singleton pregnancies from the Swedish Birth Registry, the rate
gestation, with increasing rates of maternal and neonatal complica-         of SGA infants increased from 2.2% in term infants to 3.8% in post-
tions, as well as operative deliveries, as pregnancy proceeded past         term infants.27
term.20 Similar ļ¬ndings were reported in a Danish population.21
                                                                            Meconium Staining and
Abnormal Fetal Growth                                                       Pulmonary Aspiration
Since the report of Clifford22 and his description of the postmature-       Almost all studies of post-term gestation report a markedly higher
dysmature neonate with wasting of subcutaneous tissue, meconium             incidence of meconium-stained amniotic ļ¬‚uid, compared with term
staining, and peeling of skin, many have focused their attention on the     pregnancies, and the greater risk of meconium aspiration syndrome in
problems of the undernourished post-term fetus. In fact, only 10% to        these infants is well recognized.17 Among those infants deļ¬ned by
20% of true post-term fetuses exhibit any of the ļ¬ndings described by       ultrasound-estimated fetal growth curves to be appropriately sized for
Clifford. Macrosomia is actually a far more common complication,            gestational age (AGA), those delivered post-term had a threefold higher
because, under most circumstances, the fetus continues to grow in           incidence of meconium aspiration and twice the risk of an Apgar score
utero. Twice as many post-term fetuses weigh more than 4000 g, com-         of less than 4 at 5 minutes, compared with term AGA infants.27 The
CHAPTER 32              Post-term Pregnancy          615
presence of oligohydramnios further complicates the risks of meco-                However, a cohort study done in Sweden showed no correlation
nium staining because of the lack of ļ¬‚uid to dilute the meconium,            between an AFI of less than 5 cm and adverse outcome.38 Similarly,
which results in thicker, more tenacious material in the oropharynx          Divon and associates,39 in a longitudinal assessment of AFI in 139
and lower in the respiratory tract.                                          women with post-term pregnancy, found an increased frequency of
                                                                             abnormal fetal heart rate tracings and meconium staining but no other
                                                                             signiļ¬cant adverse fetal outcome. Alļ¬revic and colleagues40 compared
                                                                             both methods with respect to pregnancy intervention in post-term
Fetal Evaluation and                                                         pregnancies and found more frequent abnormal AFIs than abnormal
Management                                                                   vertical pocket depths, leading to more inductions and fetal monitor-
                                                                             ing but no difference in perinatal outcome. Morris and colleagues41
When one considers the rapidly accelerating risk of fetal morbidity and      conducted a prospective, double-blinded, cohort study to determine
mortality between 42 and 43 weeksā€™ gestation and again between 43            whether an AFI of less than 5 cm or a single vertical pocket of less than
and 44 weeksā€™ gestation (see Fig. 32-1), it becomes apparent that no         2 cm was superior in predicting adverse perinatal events. They found
historically derived or laboratory-measured fetal age provides the pre-      the AFI to be signiļ¬cantly more associated with birth asphyxia and
cision required in the management of the post-term pregnancy. Tra-           meconium aspiration, but with poor sensitivity. More recently, Zhang
ditional landmarks, such as LMP, uterine size, and ļ¬rst auscultation of      and associates,42 using data from the Routine Antenatal Diagnostic
fetal heart tones, can miscalculate gestational age by 2 weeks or more.      Imaging with Ultrasound (RADIUS) study, compared a large popula-
Even sensitive sonographic determinations, such as crown-to-rump             tion of women screened by ultrasound to control subjects and observed
length in the ļ¬rst trimester, demonstrate a range of several days. In        that women with isolated oligohydramnios had no greater adverse
fact, in any given gestation, the actual fetal age is known only if the      perinatal events or impaired growth. Another study comparing the two
time of ovulation and conception have been studied, as in ovulation          techniques showed that the single vertical pocket method used for
induction and in vitro fertilization. Therefore, a gravida thought to be     antepartum surveillance led to less frequent diagnosis and intervention
at 41 to 42 weeks or further in gestation, in current practice, either       for oligohydramnios, but without any difference in adverse perinatal
is induced and delivered or undergoes meticulous antenatal                   outcomes.43
monitoring.                                                                       Given these disparate ļ¬ndings, it is not difļ¬cult to understand why
                                                                             there is no consensus as to the reliability or superiority of either tech-
                                                                             nique for identiļ¬cation of the fetus at risk in prolonged pregnancy.
Antenatal Fetal Monitoring                                                   Therefore, it is reasonable to conclude that an AFI of less than 5 cm,
Despite the lack of randomized clinical trials, it is generally accepted     particularly if it has been falling sharply over a short time interval, or
that careful antepartum and intrapartum fetal monitoring can virtu-          the absence of a single identiļ¬able vertical pocket of greater than 2 cm,
ally eliminate fetal post-term mortality and reduce fetal morbidity.28-32    indicates that delivery is warranted. Conversely, it is also reasonable to
However, a careful evidence-based literature analysis concluded that         consider that the ļ¬nding of a normal amniotic ļ¬‚uid volume implies
data were insufļ¬cient to determine whether routine antenatal surveil-        little fetal risk.
lance before 41 weeksā€™ gestation improves outcome or which type of                There does not appear to be any value in monitoring Doppler ļ¬‚ow
monitoring and frequency are most appropriate.33 Consequently, most          velocity in fetal vessels, inasmuch as there is no correlation between
obstetricians initiate antenatal testing at 41 weeksā€™ gestation and repeat   the ļ¬ndings and outcome.44 Zimmerman and associates45 demon-
the testing twice weekly. This testing consists of either a biophysical      strated that the sensitivity of umbilical artery velocimetry for predict-
proļ¬le (BPP) or a nonstress test and assessment of amniotic ļ¬‚uid             ing poor outcome was 7%.
volume.
    In a study of 307 women whose pregnancies had proceeded beyond
294 days, a normal twice-weekly BPP that included normal amniotic
                                                                             Fetal Monitoring versus
ļ¬‚uid volume resulted in no perinatal mortalities, and morbidity was          Induction of Labor
equivalent to that observed in a comparison group undergoing elective        Even though antenatal monitoring can virtually eliminate perinatal
labor induction with a favorable cervix.32 Based on a cumulative expe-       mortality in the post-term gestation, some morbidityā€”including
rience with 19,221 high-risk pregnancies, the same investigative group       meconium staining, increased cesarean delivery for a diagnosis of fetal
recommended delivery if amniotic ļ¬‚uid volume decreases.34                    distress, and macrosomia with its associated complicationsā€”still
    The technique used to assess amniotic ļ¬‚uid volume and its role in        exists. Although the frequency of morbid events is very low, the
evaluation of the prolonged gestation remains controversial because of       continuing concern has been addressed by an alternative approachā€”
conļ¬‚icting studies regarding which of the two tests of volume (amni-         that of cervical ripening followed by induction at 41 or 42 weeksā€™
otic ļ¬‚uid index [AFI] or single vertical pocket) is the better predictor     gestation.
of outcome and the possibility that the AFI may lead to too many                 Comparison of these two management approaches in several ran-
unnecessary interventions. Oligohydramnios is thought to be a marker         domized controlled trials has yielded generally similar results. Hannah
for fetal complications, including umbilical cord compresssion, hypox-       and coauthors46 studied 3407 women with uncomplicated pregnancies
emia, and meconium aspiration, as well as fetal heart rate abnormali-        at 41 or more weeksā€™ duration, who were randomly assigned to
ties and risk of neonatal admission to an intensive care unit.35-37          either elective induction after cervical ripening with prostaglandin E2
Bochner and coworkers36 observed an almost 24-fold increase in cesar-        (PGE2) gel or serial antenatal monitoring (fetal kicks, nonstress test,
ean delivery for the indication of fetal distress when the maximum           amniotic ļ¬‚uid). In the monitored group, labor was induced only if
vertical amniotic ļ¬‚uid pocket depth was less than 3 cm. The incidence        there was evidence of compromised fetal status. The authors observed
of meconium-stained amniotic ļ¬‚uid in the post-term gestation was             a lower rate of cesarean delivery for a diagnosis of fetal distress in the
37% among those women with adequate amniotic ļ¬‚uid volume but                 induction group but no signiļ¬cant difference between the two groups
increased to 71% if the amniotic ļ¬‚uid volume was decreased.31                in fetal mortality or morbidity. The same investigators subsequently
616      CHAPTER 32              Post-term Pregnancy

reported that routine induction was more cost-effective than serial          including a signiļ¬cant risk of postpartum hemorrhage and an increased
antenatal monitoring.47 The Maternal-Fetal Medicine Network pro-             risk of cesarean delivery.
spectively evaluated 440 patients, comparing induction with serial               The Bishop score,53 or some suitable modiļ¬cation of it, can be used
monitoring.48 They observed no fetal deaths in either group, and rates       as a guide to select the most appropriate induction technique. This is
of neonatal morbidity and cesarean delivery were similar. A more             especially true in primigravid women. If the Bishop score is lower than
recent study from Norway, in which 254 women at 41 weeksā€™ gestation          5, amniotomy and oxytocin infusion are associated with an unaccept-
were randomly assigned to an induction or expectant manage-                  ably high incidence of unsuccessful inductions as well as fetal and
ment group, found no differences in neonatal outcomes or mode of             maternal complications.54 In these circumstances, cervical ripening
delivery.49                                                                  should be undertaken before uterine contractions are provoked. Given
    These combined trials have led to the conclusion that neither            the rapidly increasing use of transvaginal ultrasound (TVUS) to assess
approach has a substantive advantage over the other. A small advantage       cervical length and dilatation and its usefulness in the diagnosis of
to the induction approach was suggested by the recent Cochrane               preterm labor, it is not unreasonable to apply this technology to cervi-
Review of 19 studies, which determined that a policy of labor induc-         cal assessment in post-term pregnancy. One study of 240 women,
tion at 41 weeks resulted in fewer fetal deaths, although the differences    comparing TVUS with digital cervical examination using receiver
and absolute risk were extremely small (1 in 2986 versus 9 in 2953;          operating characteristic (ROC) curves, demonstrated that a cervical
odds ratio, 0.3; CI, 0.9 to 0.99). There was no signiļ¬cant difference in     length of 28 mm was a better predictor of induction success (vaginal
the cesarean section rate.50                                                 delivery within 24 hours) than the Bishop score.55 However, conļ¬‚icting
    Nevertheless, in terms of physician preferences in the United States,    ļ¬ndings were reported by Chandra and associates.56
induction at 41 weeks has become the mode of practice and the debate             The most frequently used current cervical ripening techniques
moot. A recent survey of 1000 randomly selected members of the               include chemical agents such as PGE2 (dinoprostone, trade names
American College of Obstetricians and Gynecologists revealed that            Prepidil and Cervidil Rx), administered vaginally or intracervically,
73% routinely induce low-risk women at 41 weeks. For women who               and misoprostol (Cytotec Rx), administered vaginally or orally. Both
decline induction, approximately 65% of physicians initiate antenatal        appear to be effective in improving the Bishop score and to result in
testing twice weekly at 41 weeks.51 It is clear that medical induction       shorter labor times and possibly fewer failed inductions. Misoprostol,
rates have increased sharply in the United States. Between 1980 and          in doses of 25 Ī¼g given vaginally every 4 hours, appears to be slightly
1996, the rate of induction doubled (from 12.9% to 25.8%), the most          more effective that dinoprostone but is associated with a higher fre-
common indication being that of the post-term pregnancy.52                   quency of uterine tachysystole. A recent review of randomized trials
                                                                             performed between 1987 and 2005 compared the two agents and con-
                                                                             ļ¬rmed that misoprostol was superior to dinoprostone at any dose and
Management Summary                                                           route of administration in terms of achieving vaginal delivery within
It seems appropriate to recommend the following steps to evaluate and        24 hours. There was no difference in the rate of cesarean delivery.57
manage the post-term gestation:                                              This study conļ¬rmed an earlier Cochrane database review which con-
                                                                             cluded that the use of vaginal misoprostol is more effective than con-
1. Although there is insufļ¬cient evidence because of the low-risk            ventional methods of cervical ripening and labor induction. Compared
   nature of either approach, current obstetric practice dictates that       with placebo, oxytocin, or intracervical or vaginal PGE2, misoprostol
   labor induction be offered between 41 and 42 weeksā€™ gestation in          resulted in increased cervical ripening, decreased use of oxytocin, and
   the presence of a favorable cervix.                                       increased rates of vaginal delivery. However, misoprostol also caused
2. If the cervix is unfavorable, alternate approaches include either         an increased rate of uterine hyperstimulation.58
   cervical ripening followed by induction of labor or twice-weekly              Vaginal inserts such as balloon catheters also have their advocates
   fetal monitoring. Delivery should be accomplished promptly if             for cervical ripening. A systematic review concluded that these mechan-
   there is evidence of fetal compromise.                                    ical dilators do not compare favorably with chemical inducing agents
3. It is prudent to use the BPP, or some modiļ¬cation of the BPP, to          in terms of delivery success rates but are associated with less uterine
   determine antenatal fetal condition.                                      hypercontactility.59



Methods of Labor Induction                                                   Developmental Effects of
The issue of labor induction and cervical ripening agents is addressed
in detail in Chapter 36 and is summarized brieļ¬‚y here.
                                                                             Post-term Gestation
    Because normal labor depends on efļ¬cient myometrial contrac-             Studies on the development of children from prolonged pregnancies
tions acting on a compliant cervix to efface and dilate it, methods of       are difļ¬cult to evaluate because investigators have not separated neo-
labor induction must take into account both components of the uterus.        nates asphyxiated in utero and growth-restricted (dysmature) post-
If the cervix is already soft, effaced, and partially dilated, intravenous   term neonates from otherwise normally born neonates. A study of
infusion of oxytocin may be sufļ¬cient to stimulate contractions. Con-        neonatal behavior among 106 dysmature infants revealed an increased
ventional practice requires amniotomy to be performed as a ļ¬rst step,        number of illnesses and sleep disorders as well as diminished social
because this procedure maximizes the effectiveness of oxytocin. If the       competence during the ļ¬rst year of life (Vineland Social Maturity
cervix is unripe, oxytocin will not cause it to ripen, and amniotomy         Scale). Also, and not unexpectedly, the incidence of fetal distress was
is inappropriate. Although labor contractions can be stimulated by           high, and those babies who were asphyxiated in utero had a higher
oxytocin, such a result is futile, because many hours of such contrac-       incidence of abnormal neurologic signs in the neonatal period.60 All
tions are required to produce any sort of change in the cervix, and the      infants had signs of desquamation of skin and wasting of subcutaneous
ensuing prolonged labor can lead to an increase in obstetric morbidity,      tissue, however, and the group of children studied was not compared
CHAPTER 32               Post-term Pregnancy            617
with any post-term children who did not have these physical ļ¬ndings                 14. Hilder L, Costeloe K, Thilaganathan B: Prolonged pregnancy: Evaluating
at birth.                                                                               gestation-speciļ¬c risks of fetal and infant mortality. BJOG 105:169-173,
    Field and coworkers61 studied a group of 40 dysmature offspring,                    1998.
all of whom had parchment-like skin and long, thin bodies. At birth,                15. Nakano R: Post-term pregnancy: A ļ¬ve year review from Osaka National
                                                                                        Hospital. Acta Obstet Gynecol Scand 51:217, 1972.
their Brazelton interaction and motor scores were lower than in
                                                                                    16. Sachs BP, Friedman EA: Results of an epidemiological study of post-date
term controls, and at 4 months they scored lower on the Denver                          pregnancy. J Reprod Med 31:162, 1986.
Developmental Scale. By 8 months, the Bayley motor scores of the                    17. Eden R, Seifert L, Winegar A, et al: Perinatal characteristics of uncompli-
post-term subjects were equivalent to those of control infants, but their               cated post-date pregnancies. Obstet Gynecol 69:296, 1987.
mental scores were slightly lower. This study differed in at least one              18. Alexander JM, McIntire DD, Leveno UJ: Forty weeks and beyond:
signiļ¬cant way from that of Lovell60: The Apgar scores at 5 minutes in                  Pregnancy outcomes by week of gestation. Obstet Gynecol 96:291, 2000.
the two groups were identical, thus partially correcting for in utero               19. Nakling J, Backe B: Pregnancy risk increases from 41 weeks of gestation.
asphyxia.                                                                               Acta Obstet Gynecol 85:663-668, 2006.
    In a large retrospective review, Zwerdling23 observed that post-term            20. Heimstad R, Romundstad PR, Eik-Nes SH, et al: Outcomes of pregnancies
infants weighing less than 2500 g had a neonatal mortality rate seven                   beyond 37 weeks of gestation. Obstet Gynecol 108:500-508, 2006.
                                                                                    21. Olesen AW, Westergaard JG, Olsen J: Perinatal and maternal complications
times that of post-term infants as a whole. This ļ¬nding conļ¬rmed the
                                                                                        related to post-term delivery: A national regiser-based study, 1978-1993.
additional risk of the dysmature growth pattern in some post-term                       Am J Obstet Gynecol 189:222-227, 2003.
infants. The increased mortality rate was observed up to 2 years of age,            22. Clifford SH: Postmaturityā€”with placental dysfunction. J Pediatr 44:1, 1954.
but at 5 years the data on growth and intelligence in Zwerdlingā€™s study             23. Zwerdling MA: Factors pertaining to prolonged pregnancy and its outcome.
population revealed no differences between prolonged-gestation and                      Pediatrics 40:202, 1967.
normal-gestation children. These ļ¬ndings were conļ¬rmed in a pro-                    24. Usher RH, Boyd ME, McLean FH, et al: Assessment of fetal risk in post-date
spective study in which 129 children born of prolonged pregnancy                        pregnancies. Am J Obstet Gynecol 158:259, 1988.
were compared with 184 term controls.62 At 1 year and again at 2 years              25. McLean FH, Boyd ME, Usher RH: Post-term infants: Too big or too small?
of age, there were no differences between the two groups with respect                   Am J Obstet Gynecol 164:619, 1991.
to intelligence scores, physical milestones, or intercurrent illnesses.             26. Pollack RN, Hauer-Pollack G, Divon MY: Macrosomia in post-dates preg-
                                                                                        nancy: The accuracy of routine ultrasonographic screening. Am J Obstet
    One recent cohort study from Denmark linked hospital records of
                                                                                        Gynecol 167:7, 1992.
277,435 pregnancies delivering at term or beyond to cases of childhood              27. Clausson B, Cnattingius S, Axelsson O: Outcomes of post-term births: The
epilepsy. The researchers found a slight increase in the incidence of                   role of fetal growth restriction and malformations. Obstet Gynecol 94:758,
epilepsy as a function of gestational age at or after 43 weeks, but only                1999.
among those infants delivered by cesarean section or other operative                28. Hauth JC, Goodman MT, Gilstrap LC III, et al: Post-term pregnancy.
delivery.63 The risk was not observed after 1 year of life. Whether this                J Obstet Gynecol 56:467, 1980.
ļ¬nding reļ¬‚ects a problem unique to advanced gestational age or com-                 29. Freeman RK, Garite TJ, Modanlou H, et al: Postdate pregnancy: Utilization
plications that required expedient delivery is unclear.                                 of contraction stress testing for primary fetal surveillance. Am J Obstet
                                                                                        Gynecol 140:128, 1981.
                                                                                    30. Eden R, Gergely RZ, Schifrin BS, et al: Comparison of antepartum testing
                                                                                        schemes for the management of the postdate pregnancy. Am J Obstet
References                                                                              Gynecol 144:683, 1982.
 1. Ballantyne JW: The problem of the postmature infant. J Obstet Gynaecol          31. Phelan JP, Platt LP, Yeh S-Y, et al: The role of ultrasound assessment of
    Br Emp 2:36, 1902.                                                                  amniotic ļ¬‚uid volume in the management of the post-date pregnancy. Am
 2. Boyd ME, Usher RH, McLean FH, et al: Obstetric consequences of post-                J Obstet Gynecol 151:304, 1984.
    maturity. Am J Obstet Gynecol 158:334, 1988.                                    32. Johnson JM, Harman CR, Lange IR, et al: Biophysical proļ¬le scoring in the
 3. Gardosi J, Vanner T, Francis A: Gestational age and induction of labour for         management of the post-term pregnancy. Am J Obstet Gynecol 154:269,
    prolonged pregnancy. BJOG 104:792, 1997.                                            1986.
 4. Taipale P, Hiilesmaa V: Predicting delivery date by ultrasound and last         33. American College of Obstetricians and Gynecologists: ACOG Practice Pat-
    menstrual period on early gestation. Obstet Gynecol 97:189, 2001.                   terns: Management of Post-term Gestation. Practice Bulletin No. 55. Wash-
 5. Olesen AW, Thomsen SG: Prediction of delivery date by sonography in                 ington, DC, ACOG, 2004.
    the ļ¬rst and second trimesters. Ultrasound Obstet Gynecol 28:292-297,           34. Manning FA, Morrison I, Harman CR, et al: Fetal assessment based on fetal
    2006.                                                                               biophysical proļ¬le scoring: Experience in 19,221 referred high risk preg-
 6. Bennett KA, Crane JM, Oā€™Shea P, et al: First trimester ultrasound screening         nancies. II: An analysis of false negative deaths. Am J Obstet Gynecol
    is effective in reducing post-term labor induction rates: A randomized              157:880, 1987.
    controlled trial. Am J Obstet Gynecol 190:1077-1081, 2004.                      35. Leveno KJ, Quirk JG, Cunningham FG, et al: Prolonged pregnancy: I.
 7. Holm LW: Prolonged pregnancy. Adv Vet Sci 11:159, 1967.                             Observations concerning the causes of fetal distress. Am J Obstet Gynecol
 8. France JT, Liggins GC: Placenta sulfatase deļ¬ciency. J Clin Endocrinol              150:465, 1984.
    29:138, 1969.                                                                   36. Bochner CJ, Medearis Al, Davis J, et al: Antepartum predictors of fetal dis-
 9. Fliegner JRH, Schindler I, Brown JB: Low urinary oestriol excretion during          tress in post-term pregnancy. Am J Obstet Gynecol 157:353, 1987.
    pregnancy associated with placental sulphatase deļ¬ciency or congenital          37. Tongsong T, Srisomboon J: Amniotic ļ¬‚uid volume as a predictor of fetal
    adrenal hypoplasia. J Obstet Gynaecol Br Commonw 79:810, 1972.                      distress in post-term pregnancy. Int J Gynaecol Obstet 40:213, 1993.
10. McLean M, Bisits S, Davies J, et al: A placental clock controlling the length   38. Montan S, Malcus P: Amniotic ļ¬‚uid index in prolonged pregnancy.
    of human pregnancy. Nat Med 1:460-463, 1995.                                        J Matern Fetal Invest 5:4, 1995.
11. Olesen AW, Basso O, Olsen J: Risk of recurrence of prolonged pregnancy.         39. Divon M, Marks AD, Henderson CE: Longitudinal measurement of amni-
    BMJ 326:476, 2003.                                                                  otic ļ¬‚uid index in post-term pregnancies and its association with fetal
12. Kistka ZA, Palomar L, Boslaugh SE, et al: Risk for posttterm delivery after         outcome. Am J Obstet Gynecol 172:142, 1995.
    previous posttterm delivery. Am J Obstet Gynecol 196:241.e1-6, 2007.            40. Alļ¬revic Z, Luckas M, Walkinshaw SA, et al: A randomized comparison
13. Butler NR, Alberman ED: The Second Report of the 1958 British Perinatal             between amniotic ļ¬‚uid index and maximum pool depth in the monitoring
    Mortality Survey. Edinburgh, E & S Livingstone, 1969, p 327.                        of post-term pregnancy. BJOG 104:207, 1997.
618      CHAPTER 32                Post-term Pregnancy

41. Morris JM, Thompson K, Smithey J, et al: The usefulness of ultrasound           52. Yawn BP, Wollan P, McKeon K, et al: Temporal changes in rates and reasons
    assessment of amniotic ļ¬‚uid in predicting adverse outcome in prolonged              for medical induction of term labor, 1980-1996. Am J Obstet Gynecol
    pregnancy: A prospective blinded observational study. BJOG 110:989-994,             184:611, 2001.
    2003.                                                                           53. Bishop EH: Pelvic scoring for elective induction. Obstet Gynecol 24:266,
42. Zhang J, Troendle J, Meikle S, et al: Isolated oligohydramnios is not associ-       1964.
    ated with adverse pregnancy outcome. BJOG 111:220-225, 2004.                    54. Calder AA, Greer CA: Cervical physiology and induction of labor. In
43. Chauhan SP, Doherty DD, Magann EF, et al: Amniotic ļ¬‚uid index vs single             Bonnar J (ed): Recent Advances in Obstetrics and Gynecology 17. Edin-
    deepest pocket technique during modiļ¬ed biophysical proļ¬le: A random-               burgh, Churchill Livingstone, 1992.
    ized clinical trial. Am J Obstet Gynecol 191:661-667, 2004.                     55. Pandis GU, Papageorghiou AJ, Ramanathan JG, et al: Preinduction sono-
44. Guidetti DA, Divon MY, Cavalieri RL, et al: Fetal umbilical artery ļ¬‚ow              graphic measurement of cervical length in the prediction of successful
    velocimetry in post-date pregnancies. Am J Obstet Gynecol 157:1521,                 induction of labor. Ultrasound Obstet Gynecol 18:623, 2001.
    1987.                                                                           56. Chandra S, Crane JMG, Hutchens D, et al: Transvaginal ultrasound and
45. Zimmerman P, Alback T, Koskinen J, et al: Doppler ļ¬‚ow velocimetry of the            digital examination in predicting successful labor induction. Obstet Gynecol
    umbilical artery, uteroplacental arteries and fetal middle cerebral artery in       98:2, 2001.
    prolonged pregnancy. Ultrasound Obstet Gynecol 5:189, 1995.                     57. Crane JM, Butler B, Young DC, et al: Misoprostol compared with prosta-
46. Hannah ME, Hannah WJ, Hellmann J, et al: Induction of labor as compared             glandin E2 for labour induction in women at term with intact membranes
    with serial antenatal monitoring in post-term pregnancy. N Engl J Med               and unfavourable cervix: A systematic review. BJOG 113:1366-1376,
    326:1587, 1992.                                                                     2006.
47. Goeree R, Hannah ME, Hweson S: Cost-effectiveness of induction of labor         58. Hofmeyr GJ, Gulmezoglu AM: Vaginal misoprostol for cervical ripening
    versus serial antenatal monitoring in the Canadian Multicentre Post-term            and induction of labour. Cochrane Database Syst Rev (1):CD000941,
    Pregnancy Trial. Canadian Med Assoc 152:1445, 1995.                                 2003.
48. National Institute of Child Health and Development (NICHD) Network of           59. Boulvain M, Kelly A, Lohse C, et al: Mechanical methods for induction of
    Maternal-Fetal Medicine Unit: A clinical trial of induction of labor versus         labour. Cochrane Database Syst Rev (4):CD000941, 2002.
    expectant management in post-term pregnancy. Am J Obstet Gynecol                60. Lovell KE: The effect of postmaturity on the developing child. Med J Austr
    170:716, 1994.                                                                      1:13, 1973.
49. Heimstad R, Skogvoll E, Mattsson L-A, et al: Induction of labor or serial       61. Field TM, Dabiri C, Hallock N, et al: Developmental effects of prolonged
    antenatal fetal monitoring in the post-term pregnancy: A randomized con-            pregnancy in the postmaturity syndrome. J Pediatr 90:836, 1977.
    trolled trial. Obstet Gynecol 109:609-617, 2007.                                62. Shime J, Librach CL, Gare DJ, et al: The inļ¬‚uence of prolonged pregnancy
50. Gulmezoglu AM, Crowther CA, Middleton P: Induction of labour for                    on infant development at one and two years of age: A prospective controlled
    improving birth outcomes for women at or beyond term. Cochrane Data-                study. Am J Obstet Gynecol 154:341, 1986.
    base Syst Rev (4):CD004945, 2006.                                               63. Ehrenstein V, Pedersen L, Holsteen V, et al: Postterm delivery and risk for
51. Cleary-Goldman J, Bettes B, Robinson JN, et al: Post-term pregnancy: Prac-          epilepsy in childhood. Pediatrics 119:554-561, 2007.
    tice patterns of contemporary obstetricians and gynecologists. Am J Peri-
    natol 23:15-20, 2006.

More Related Content

What's hot

Prevention of Prematurity and Stillbirth_Litch_10.11.12
Prevention of Prematurity and Stillbirth_Litch_10.11.12Prevention of Prematurity and Stillbirth_Litch_10.11.12
Prevention of Prematurity and Stillbirth_Litch_10.11.12
CORE Group
Ā 
Breastfeeding And The Risk Of Postneonatal Death In The United States
Breastfeeding And The Risk Of Postneonatal Death In The United StatesBreastfeeding And The Risk Of Postneonatal Death In The United States
Breastfeeding And The Risk Of Postneonatal Death In The United States
Biblioteca Virtual
Ā 
Nasa hukay ang isang paa ng manganganak
Nasa hukay ang isang paa ng manganganakNasa hukay ang isang paa ng manganganak
Nasa hukay ang isang paa ng manganganak
Carmen Columna
Ā 
Diagnostic approach and management of extrauterine pregnancy
Diagnostic approach and management of extrauterine pregnancyDiagnostic approach and management of extrauterine pregnancy
Diagnostic approach and management of extrauterine pregnancy
Rustem Celami
Ā 
1st pia. 2
1st pia. 21st pia. 2
1st pia. 2
Edwin Chan
Ā 
1st pia. 2
1st pia. 21st pia. 2
1st pia. 2
Edwin Chan
Ā 
Hp mar06 rqectopic
Hp mar06 rqectopicHp mar06 rqectopic
Hp mar06 rqectopic
Abeer Ahmed
Ā 

What's hot (20)

Fetal fraction nipt pnd
Fetal fraction nipt pndFetal fraction nipt pnd
Fetal fraction nipt pnd
Ā 
Arteria Uterina Primer Trimestre Y Rciu
Arteria Uterina Primer Trimestre Y RciuArteria Uterina Primer Trimestre Y Rciu
Arteria Uterina Primer Trimestre Y Rciu
Ā 
10.1148@rg.2016160080
10.1148@rg.201616008010.1148@rg.2016160080
10.1148@rg.2016160080
Ā 
Breastfeeding in Women with Covid19 infection-Expert group meeting for develo...
Breastfeeding in Women with Covid19 infection-Expert group meeting for develo...Breastfeeding in Women with Covid19 infection-Expert group meeting for develo...
Breastfeeding in Women with Covid19 infection-Expert group meeting for develo...
Ā 
Prevention of Prematurity and Stillbirth_Litch_10.11.12
Prevention of Prematurity and Stillbirth_Litch_10.11.12Prevention of Prematurity and Stillbirth_Litch_10.11.12
Prevention of Prematurity and Stillbirth_Litch_10.11.12
Ā 
Twin pregnancy
Twin pregnancyTwin pregnancy
Twin pregnancy
Ā 
Miscarriage
 Miscarriage Miscarriage
Miscarriage
Ā 
Manejo de embarazo a termino tardio y postermino
Manejo de embarazo a termino tardio y posterminoManejo de embarazo a termino tardio y postermino
Manejo de embarazo a termino tardio y postermino
Ā 
Breastfeeding And The Risk Of Postneonatal Death In The United States
Breastfeeding And The Risk Of Postneonatal Death In The United StatesBreastfeeding And The Risk Of Postneonatal Death In The United States
Breastfeeding And The Risk Of Postneonatal Death In The United States
Ā 
Stillbirth
StillbirthStillbirth
Stillbirth
Ā 
Long term survival NBL
Long term survival NBLLong term survival NBL
Long term survival NBL
Ā 
Nasa hukay ang isang paa ng manganganak
Nasa hukay ang isang paa ng manganganakNasa hukay ang isang paa ng manganganak
Nasa hukay ang isang paa ng manganganak
Ā 
Diagnostic approach and management of extrauterine pregnancy
Diagnostic approach and management of extrauterine pregnancyDiagnostic approach and management of extrauterine pregnancy
Diagnostic approach and management of extrauterine pregnancy
Ā 
Posterm EBM- warda
Posterm EBM-   wardaPosterm EBM-   warda
Posterm EBM- warda
Ā 
1st pia. 2
1st pia. 21st pia. 2
1st pia. 2
Ā 
1st pia. 2
1st pia. 21st pia. 2
1st pia. 2
Ā 
exome sequencing improves genetic diagnosis of fetal increased nuchal translu...
exome sequencing improves genetic diagnosis of fetal increased nuchal translu...exome sequencing improves genetic diagnosis of fetal increased nuchal translu...
exome sequencing improves genetic diagnosis of fetal increased nuchal translu...
Ā 
Hp mar06 rqectopic
Hp mar06 rqectopicHp mar06 rqectopic
Hp mar06 rqectopic
Ā 
Lactancia materna y riesgo de cancer infantil
Lactancia materna y riesgo de cancer infantilLactancia materna y riesgo de cancer infantil
Lactancia materna y riesgo de cancer infantil
Ā 
Quįŗ£n lĆ½ nhau cĆ i răng lĘ°į»£c ACOG 2015 placenta accreta management
Quįŗ£n lĆ½ nhau cĆ i răng lĘ°į»£c ACOG 2015 placenta accreta managementQuįŗ£n lĆ½ nhau cĆ i răng lĘ°į»£c ACOG 2015 placenta accreta management
Quįŗ£n lĆ½ nhau cĆ i răng lĘ°į»£c ACOG 2015 placenta accreta management
Ā 

Viewers also liked

SecondMarket_School Project1
SecondMarket_School Project1SecondMarket_School Project1
SecondMarket_School Project1
rokererick
Ā 
National geographicphotos
National geographicphotosNational geographicphotos
National geographicphotos
Orlei Almeida
Ā 
Jea wiki slideshare conference 2014
Jea wiki slideshare  conference 2014Jea wiki slideshare  conference 2014
Jea wiki slideshare conference 2014
Sara Shapiro-Plevan
Ā 
In what ways does your media product use, develop or challenge forms and conv...
In what ways does your media product use, develop or challenge forms and conv...In what ways does your media product use, develop or challenge forms and conv...
In what ways does your media product use, develop or challenge forms and conv...
sarazanj
Ā 

Viewers also liked (20)

How to avoid being fooled by percent changes
How to avoid being fooled by percent changesHow to avoid being fooled by percent changes
How to avoid being fooled by percent changes
Ā 
2014 Honda CR-V Serving Jackson | MS Patty Peck Honda
2014 Honda CR-V Serving Jackson | MS Patty Peck Honda2014 Honda CR-V Serving Jackson | MS Patty Peck Honda
2014 Honda CR-V Serving Jackson | MS Patty Peck Honda
Ā 
Research based writing
Research based writingResearch based writing
Research based writing
Ā 
modeveast 2012 Appcelerator Alloy & Cloud Services Presentation
modeveast 2012 Appcelerator Alloy & Cloud Services Presentationmodeveast 2012 Appcelerator Alloy & Cloud Services Presentation
modeveast 2012 Appcelerator Alloy & Cloud Services Presentation
Ā 
The Potential for Mobile in Interpreting Manuscripts
The Potential for Mobile in Interpreting ManuscriptsThe Potential for Mobile in Interpreting Manuscripts
The Potential for Mobile in Interpreting Manuscripts
Ā 
MS 2014 Honda Pilot | Honda Dealer Serving Jackson
MS 2014 Honda Pilot | Honda Dealer Serving JacksonMS 2014 Honda Pilot | Honda Dealer Serving Jackson
MS 2014 Honda Pilot | Honda Dealer Serving Jackson
Ā 
SecondMarket_School Project1
SecondMarket_School Project1SecondMarket_School Project1
SecondMarket_School Project1
Ā 
National geographicphotos
National geographicphotosNational geographicphotos
National geographicphotos
Ā 
Continous Integration
Continous IntegrationContinous Integration
Continous Integration
Ā 
Copyright basics
Copyright basicsCopyright basics
Copyright basics
Ā 
Jea wiki slideshare conference 2014
Jea wiki slideshare  conference 2014Jea wiki slideshare  conference 2014
Jea wiki slideshare conference 2014
Ā 
2016 Honda CR-V Brochure | Jackson Area Honda Dealer
2016 Honda CR-V Brochure | Jackson Area Honda Dealer2016 Honda CR-V Brochure | Jackson Area Honda Dealer
2016 Honda CR-V Brochure | Jackson Area Honda Dealer
Ā 
Workflow Foundation
Workflow FoundationWorkflow Foundation
Workflow Foundation
Ā 
In what ways does your media product use, develop or challenge forms and conv...
In what ways does your media product use, develop or challenge forms and conv...In what ways does your media product use, develop or challenge forms and conv...
In what ways does your media product use, develop or challenge forms and conv...
Ā 
SubAid User Guide - Overview
SubAid User Guide - OverviewSubAid User Guide - Overview
SubAid User Guide - Overview
Ā 
SQLDay2011_Sesja01_ModelowanieIZasilanieWymiarĆ³wHurtowniDanych_ŁukaszGrala
SQLDay2011_Sesja01_ModelowanieIZasilanieWymiarĆ³wHurtowniDanych_ŁukaszGralaSQLDay2011_Sesja01_ModelowanieIZasilanieWymiarĆ³wHurtowniDanych_ŁukaszGrala
SQLDay2011_Sesja01_ModelowanieIZasilanieWymiarĆ³wHurtowniDanych_ŁukaszGrala
Ā 
Identify & Unlock Your Mobile Strategy
Identify & Unlock Your Mobile StrategyIdentify & Unlock Your Mobile Strategy
Identify & Unlock Your Mobile Strategy
Ā 
2016 Honda Fit Brochure | Honda Dealer Near Jackson
2016 Honda Fit Brochure | Honda Dealer Near Jackson2016 Honda Fit Brochure | Honda Dealer Near Jackson
2016 Honda Fit Brochure | Honda Dealer Near Jackson
Ā 
Windows Azure platform
Windows Azure platformWindows Azure platform
Windows Azure platform
Ā 
Microsoft NUI - Kinect
Microsoft NUI - KinectMicrosoft NUI - Kinect
Microsoft NUI - Kinect
Ā 

Similar to 4 u1.0-b978-1-4160-4224-2..50035-1..docpdf

Management-of-Postterm-Pregnancy
Management-of-Postterm-PregnancyManagement-of-Postterm-Pregnancy
Management-of-Postterm-Pregnancy
Dr Ufaque Batool Korai
Ā 
perineal outcome after restrictive use of episiotomy
perineal outcome after restrictive use of episiotomyperineal outcome after restrictive use of episiotomy
perineal outcome after restrictive use of episiotomy
arbin joshi
Ā 
Periodontitis paper
Periodontitis paper Periodontitis paper
Periodontitis paper
Megan Leifson
Ā 
Association between obstetrician_forceps_volume.5
Association between obstetrician_forceps_volume.5Association between obstetrician_forceps_volume.5
Association between obstetrician_forceps_volume.5
Luis Carlos Murillo Valencia
Ā 
Infant Formula Contaminated By Enterobacteria
Infant Formula Contaminated By EnterobacteriaInfant Formula Contaminated By Enterobacteria
Infant Formula Contaminated By Enterobacteria
Biblioteca Virtual
Ā 
Coccidioidomycosis in pregnancy
Coccidioidomycosis in pregnancyCoccidioidomycosis in pregnancy
Coccidioidomycosis in pregnancy
Babak Jebelli
Ā 

Similar to 4 u1.0-b978-1-4160-4224-2..50035-1..docpdf (20)

Management-of-Postterm-Pregnancy
Management-of-Postterm-PregnancyManagement-of-Postterm-Pregnancy
Management-of-Postterm-Pregnancy
Ā 
Repeat steroids when is it okay review 2012 ron wapner
Repeat steroids when is it okay review 2012 ron wapnerRepeat steroids when is it okay review 2012 ron wapner
Repeat steroids when is it okay review 2012 ron wapner
Ā 
Iris Publishers - journal of gynecology | World Journal of Gynecology & Women...
Iris Publishers - journal of gynecology | World Journal of Gynecology & Women...Iris Publishers - journal of gynecology | World Journal of Gynecology & Women...
Iris Publishers - journal of gynecology | World Journal of Gynecology & Women...
Ā 
cerclage for multiple pregnancy
cerclage for multiple pregnancycerclage for multiple pregnancy
cerclage for multiple pregnancy
Ā 
Post term pregnancy
Post term pregnancyPost term pregnancy
Post term pregnancy
Ā 
perineal outcome after restrictive use of episiotomy
perineal outcome after restrictive use of episiotomyperineal outcome after restrictive use of episiotomy
perineal outcome after restrictive use of episiotomy
Ā 
Periodontitis paper
Periodontitis paper Periodontitis paper
Periodontitis paper
Ā 
Association between obstetrician_forceps_volume.5
Association between obstetrician_forceps_volume.5Association between obstetrician_forceps_volume.5
Association between obstetrician_forceps_volume.5
Ā 
Preterm labor & PROM
Preterm labor & PROMPreterm labor & PROM
Preterm labor & PROM
Ā 
Postterm pregnancy
Postterm pregnancyPostterm pregnancy
Postterm pregnancy
Ā 
A Clinical Study on Maternal and Fetal Outcome in Multiple Pregnancies in Wom...
A Clinical Study on Maternal and Fetal Outcome in Multiple Pregnancies in Wom...A Clinical Study on Maternal and Fetal Outcome in Multiple Pregnancies in Wom...
A Clinical Study on Maternal and Fetal Outcome in Multiple Pregnancies in Wom...
Ā 
recurrent abortion
 recurrent abortion   recurrent abortion
recurrent abortion
Ā 
Diagnosis and surveillance of late onset fetal growth restriction 2018
Diagnosis and surveillance of late onset fetal growth restriction 2018Diagnosis and surveillance of late onset fetal growth restriction 2018
Diagnosis and surveillance of late onset fetal growth restriction 2018
Ā 
The comparison of dinoprostone and vagiprost for induction of lobar in post t...
The comparison of dinoprostone and vagiprost for induction of lobar in post t...The comparison of dinoprostone and vagiprost for induction of lobar in post t...
The comparison of dinoprostone and vagiprost for induction of lobar in post t...
Ā 
The Natural History Of The Normal First Stage Of 6[1]
The Natural History Of The Normal First Stage Of 6[1]The Natural History Of The Normal First Stage Of 6[1]
The Natural History Of The Normal First Stage Of 6[1]
Ā 
Infant Formula Contaminated By Enterobacteria
Infant Formula Contaminated By EnterobacteriaInfant Formula Contaminated By Enterobacteria
Infant Formula Contaminated By Enterobacteria
Ā 
Best Ivf Specialist Doctor Dr. K.D.Nayar Clinic in Delhi
Best Ivf Specialist Doctor Dr. K.D.Nayar Clinic in DelhiBest Ivf Specialist Doctor Dr. K.D.Nayar Clinic in Delhi
Best Ivf Specialist Doctor Dr. K.D.Nayar Clinic in Delhi
Ā 
ABORTION.ppt
ABORTION.pptABORTION.ppt
ABORTION.ppt
Ā 
somya.pptx
somya.pptxsomya.pptx
somya.pptx
Ā 
Coccidioidomycosis in pregnancy
Coccidioidomycosis in pregnancyCoccidioidomycosis in pregnancy
Coccidioidomycosis in pregnancy
Ā 

More from Loveis1able Khumpuangdee

ą¹ąø™ąø§ąø—ąø²ąø‡ąøąø²ąø£ąø”ąø²ą¹€ąø™ ą¹ ąø™ąø‡ąø²ąø™ąø› ąø“ ąø­ąø‡ąø ą¹‰ ąø™ąø„ąø§ąøšąø„ ąø± ąø”ąøąø²ąø£ąø£ąø°ąøšąø²ąø”ąø‚ąø­ąø‡ą¹‚ąø£ąø„ąø” ąøø ąø·ąø­ ą¹€ąø—ą¹‰ąø² ąø›ąø²ąø ąøŖą¹ąø²ąø«ąø£ąøšą¹ąøž...
ą¹ąø™ąø§ąø—ąø²ąø‡ąøąø²ąø£ąø”ąø²ą¹€ąø™ ą¹ ąø™ąø‡ąø²ąø™ąø› ąø“ ąø­ąø‡ąø ą¹‰ ąø™ąø„ąø§ąøšąø„ ąø± ąø”ąøąø²ąø£ąø£ąø°ąøšąø²ąø”ąø‚ąø­ąø‡ą¹‚ąø£ąø„ąø” ąøø ąø·ąø­ ą¹€ąø—ą¹‰ąø² ąø›ąø²ąø ąøŖą¹ąø²ąø«ąø£ąøšą¹ąøž...ą¹ąø™ąø§ąø—ąø²ąø‡ąøąø²ąø£ąø”ąø²ą¹€ąø™ ą¹ ąø™ąø‡ąø²ąø™ąø› ąø“ ąø­ąø‡ąø ą¹‰ ąø™ąø„ąø§ąøšąø„ ąø± ąø”ąøąø²ąø£ąø£ąø°ąøšąø²ąø”ąø‚ąø­ąø‡ą¹‚ąø£ąø„ąø” ąøø ąø·ąø­ ą¹€ąø—ą¹‰ąø² ąø›ąø²ąø ąøŖą¹ąø²ąø«ąø£ąøšą¹ąøž...
ą¹ąø™ąø§ąø—ąø²ąø‡ąøąø²ąø£ąø”ąø²ą¹€ąø™ ą¹ ąø™ąø‡ąø²ąø™ąø› ąø“ ąø­ąø‡ąø ą¹‰ ąø™ąø„ąø§ąøšąø„ ąø± ąø”ąøąø²ąø£ąø£ąø°ąøšąø²ąø”ąø‚ąø­ąø‡ą¹‚ąø£ąø„ąø” ąøø ąø·ąø­ ą¹€ąø—ą¹‰ąø² ąø›ąø²ąø ąøŖą¹ąø²ąø«ąø£ąøšą¹ąøž...
Loveis1able Khumpuangdee
Ā 

More from Loveis1able Khumpuangdee (20)

Rollup01
Rollup01Rollup01
Rollup01
Ā 
Protec
ProtecProtec
Protec
Ā 
Factsheet hfm
Factsheet hfmFactsheet hfm
Factsheet hfm
Ā 
Factsheet
FactsheetFactsheet
Factsheet
Ā 
Eidnotebook54
Eidnotebook54Eidnotebook54
Eidnotebook54
Ā 
Data l3 148
Data l3 148Data l3 148
Data l3 148
Ā 
Data l3 147
Data l3 147Data l3 147
Data l3 147
Ā 
Data l3 127
Data l3 127Data l3 127
Data l3 127
Ā 
Data l3 126
Data l3 126Data l3 126
Data l3 126
Ā 
Data l3 113
Data l3 113Data l3 113
Data l3 113
Ā 
Data l3 112
Data l3 112Data l3 112
Data l3 112
Ā 
Data l3 92
Data l3 92Data l3 92
Data l3 92
Ā 
Data l3 89
Data l3 89Data l3 89
Data l3 89
Ā 
Data l2 80
Data l2 80Data l2 80
Data l2 80
Ā 
Hfm reccomment10072555
Hfm reccomment10072555Hfm reccomment10072555
Hfm reccomment10072555
Ā 
Hfm work2550
Hfm work2550Hfm work2550
Hfm work2550
Ā 
Factsheet hfm
Factsheet hfmFactsheet hfm
Factsheet hfm
Ā 
Publichealth
PublichealthPublichealth
Publichealth
Ā 
ą¹ąø™ąø§ąø—ąø²ąø‡ąøąø²ąø£ąø”ąø²ą¹€ąø™ ą¹ ąø™ąø‡ąø²ąø™ąø› ąø“ ąø­ąø‡ąø ą¹‰ ąø™ąø„ąø§ąøšąø„ ąø± ąø”ąøąø²ąø£ąø£ąø°ąøšąø²ąø”ąø‚ąø­ąø‡ą¹‚ąø£ąø„ąø” ąøø ąø·ąø­ ą¹€ąø—ą¹‰ąø² ąø›ąø²ąø ąøŖą¹ąø²ąø«ąø£ąøšą¹ąøž...
ą¹ąø™ąø§ąø—ąø²ąø‡ąøąø²ąø£ąø”ąø²ą¹€ąø™ ą¹ ąø™ąø‡ąø²ąø™ąø› ąø“ ąø­ąø‡ąø ą¹‰ ąø™ąø„ąø§ąøšąø„ ąø± ąø”ąøąø²ąø£ąø£ąø°ąøšąø²ąø”ąø‚ąø­ąø‡ą¹‚ąø£ąø„ąø” ąøø ąø·ąø­ ą¹€ąø—ą¹‰ąø² ąø›ąø²ąø ąøŖą¹ąø²ąø«ąø£ąøšą¹ąøž...ą¹ąø™ąø§ąø—ąø²ąø‡ąøąø²ąø£ąø”ąø²ą¹€ąø™ ą¹ ąø™ąø‡ąø²ąø™ąø› ąø“ ąø­ąø‡ąø ą¹‰ ąø™ąø„ąø§ąøšąø„ ąø± ąø”ąøąø²ąø£ąø£ąø°ąøšąø²ąø”ąø‚ąø­ąø‡ą¹‚ąø£ąø„ąø” ąøø ąø·ąø­ ą¹€ąø—ą¹‰ąø² ąø›ąø²ąø ąøŖą¹ąø²ąø«ąø£ąøšą¹ąøž...
ą¹ąø™ąø§ąø—ąø²ąø‡ąøąø²ąø£ąø”ąø²ą¹€ąø™ ą¹ ąø™ąø‡ąø²ąø™ąø› ąø“ ąø­ąø‡ąø ą¹‰ ąø™ąø„ąø§ąøšąø„ ąø± ąø”ąøąø²ąø£ąø£ąø°ąøšąø²ąø”ąø‚ąø­ąø‡ą¹‚ąø£ąø„ąø” ąøø ąø·ąø­ ą¹€ąø—ą¹‰ąø² ąø›ąø²ąø ąøŖą¹ąø²ąø«ąø£ąøšą¹ąøž...
Ā 
hand foot mouth
hand foot mouthhand foot mouth
hand foot mouth
Ā 

Recently uploaded

Cara Menggugurkan Kandungan Dengan Cepat Selesai Dalam 24 Jam Secara Alami Bu...
Cara Menggugurkan Kandungan Dengan Cepat Selesai Dalam 24 Jam Secara Alami Bu...Cara Menggugurkan Kandungan Dengan Cepat Selesai Dalam 24 Jam Secara Alami Bu...
Cara Menggugurkan Kandungan Dengan Cepat Selesai Dalam 24 Jam Secara Alami Bu...
Cara Menggugurkan Kandungan 087776558899
Ā 
ā¤ļø Chandigarh Call Girlsā˜Žļø98151-579OOā˜Žļø Call Girl service in Chandigarh ā˜Žļø Ch...
ā¤ļø Chandigarh Call Girlsā˜Žļø98151-579OOā˜Žļø Call Girl service in Chandigarh ā˜Žļø Ch...ā¤ļø Chandigarh Call Girlsā˜Žļø98151-579OOā˜Žļø Call Girl service in Chandigarh ā˜Žļø Ch...
ā¤ļø Chandigarh Call Girlsā˜Žļø98151-579OOā˜Žļø Call Girl service in Chandigarh ā˜Žļø Ch...
Rashmi Entertainment
Ā 
Difference Between Skeletal Smooth and Cardiac Muscles
Difference Between Skeletal Smooth and Cardiac MusclesDifference Between Skeletal Smooth and Cardiac Muscles
Difference Between Skeletal Smooth and Cardiac Muscles
MedicoseAcademics
Ā 
šŸ‘‰ Chennai Sexy Auntyā€™s WhatsApp Number šŸ‘‰šŸ“ž 7427069034 šŸ‘‰šŸ“ž JustšŸ“² Call Ruhi Colle...
šŸ‘‰ Chennai Sexy Auntyā€™s WhatsApp Number šŸ‘‰šŸ“ž 7427069034 šŸ‘‰šŸ“ž JustšŸ“² Call Ruhi Colle...šŸ‘‰ Chennai Sexy Auntyā€™s WhatsApp Number šŸ‘‰šŸ“ž 7427069034 šŸ‘‰šŸ“ž JustšŸ“² Call Ruhi Colle...
šŸ‘‰ Chennai Sexy Auntyā€™s WhatsApp Number šŸ‘‰šŸ“ž 7427069034 šŸ‘‰šŸ“ž JustšŸ“² Call Ruhi Colle...
rajnisinghkjn
Ā 
Russian Call Girls In Pune šŸ‘‰ Just CALL ME: 9352988975 āœ…ā¤ļøšŸ’Ælow cost unlimited ...
Russian Call Girls In Pune šŸ‘‰ Just CALL ME: 9352988975 āœ…ā¤ļøšŸ’Ælow cost unlimited ...Russian Call Girls In Pune šŸ‘‰ Just CALL ME: 9352988975 āœ…ā¤ļøšŸ’Ælow cost unlimited ...
Russian Call Girls In Pune šŸ‘‰ Just CALL ME: 9352988975 āœ…ā¤ļøšŸ’Ælow cost unlimited ...
chanderprakash5506
Ā 

Recently uploaded (20)

šŸ’°Call Girl In Bangaloreā˜Žļø63788-78445šŸ’° Call Girl service in Bangaloreā˜ŽļøBangalo...
šŸ’°Call Girl In Bangaloreā˜Žļø63788-78445šŸ’° Call Girl service in Bangaloreā˜ŽļøBangalo...šŸ’°Call Girl In Bangaloreā˜Žļø63788-78445šŸ’° Call Girl service in Bangaloreā˜ŽļøBangalo...
šŸ’°Call Girl In Bangaloreā˜Žļø63788-78445šŸ’° Call Girl service in Bangaloreā˜ŽļøBangalo...
Ā 
Call 8250092165 Patna Call Girls ā‚¹4.5k Cash Payment With Room Delivery
Call 8250092165 Patna Call Girls ā‚¹4.5k Cash Payment With Room DeliveryCall 8250092165 Patna Call Girls ā‚¹4.5k Cash Payment With Room Delivery
Call 8250092165 Patna Call Girls ā‚¹4.5k Cash Payment With Room Delivery
Ā 
Cara Menggugurkan Kandungan Dengan Cepat Selesai Dalam 24 Jam Secara Alami Bu...
Cara Menggugurkan Kandungan Dengan Cepat Selesai Dalam 24 Jam Secara Alami Bu...Cara Menggugurkan Kandungan Dengan Cepat Selesai Dalam 24 Jam Secara Alami Bu...
Cara Menggugurkan Kandungan Dengan Cepat Selesai Dalam 24 Jam Secara Alami Bu...
Ā 
(RIYA)šŸŽ„Airhostess Call Girl Jaipur Call Now 8445551418 Premium Collection Of ...
(RIYA)šŸŽ„Airhostess Call Girl Jaipur Call Now 8445551418 Premium Collection Of ...(RIYA)šŸŽ„Airhostess Call Girl Jaipur Call Now 8445551418 Premium Collection Of ...
(RIYA)šŸŽ„Airhostess Call Girl Jaipur Call Now 8445551418 Premium Collection Of ...
Ā 
ā¤ļø Chandigarh Call Girlsā˜Žļø98151-579OOā˜Žļø Call Girl service in Chandigarh ā˜Žļø Ch...
ā¤ļø Chandigarh Call Girlsā˜Žļø98151-579OOā˜Žļø Call Girl service in Chandigarh ā˜Žļø Ch...ā¤ļø Chandigarh Call Girlsā˜Žļø98151-579OOā˜Žļø Call Girl service in Chandigarh ā˜Žļø Ch...
ā¤ļø Chandigarh Call Girlsā˜Žļø98151-579OOā˜Žļø Call Girl service in Chandigarh ā˜Žļø Ch...
Ā 
Difference Between Skeletal Smooth and Cardiac Muscles
Difference Between Skeletal Smooth and Cardiac MusclesDifference Between Skeletal Smooth and Cardiac Muscles
Difference Between Skeletal Smooth and Cardiac Muscles
Ā 
Call Girls Mussoorie Just Call 8854095900 Top Class Call Girl Service Available
Call Girls Mussoorie Just Call 8854095900 Top Class Call Girl Service AvailableCall Girls Mussoorie Just Call 8854095900 Top Class Call Girl Service Available
Call Girls Mussoorie Just Call 8854095900 Top Class Call Girl Service Available
Ā 
Call Girls Service Jaipur {9521753030 } ā¤ļøVVIP BHAWNA Call Girl in Jaipur Raj...
Call Girls Service Jaipur {9521753030 } ā¤ļøVVIP BHAWNA Call Girl in Jaipur Raj...Call Girls Service Jaipur {9521753030 } ā¤ļøVVIP BHAWNA Call Girl in Jaipur Raj...
Call Girls Service Jaipur {9521753030 } ā¤ļøVVIP BHAWNA Call Girl in Jaipur Raj...
Ā 
Lucknow Call Girls Service { 9984666624 } ā¤ļøVVIP ROCKY Call Girl in Lucknow U...
Lucknow Call Girls Service { 9984666624 } ā¤ļøVVIP ROCKY Call Girl in Lucknow U...Lucknow Call Girls Service { 9984666624 } ā¤ļøVVIP ROCKY Call Girl in Lucknow U...
Lucknow Call Girls Service { 9984666624 } ā¤ļøVVIP ROCKY Call Girl in Lucknow U...
Ā 
7 steps How to prevent Thalassemia : Dr Sharda Jain & Vandana Gupta
7 steps How to prevent Thalassemia : Dr Sharda Jain & Vandana Gupta7 steps How to prevent Thalassemia : Dr Sharda Jain & Vandana Gupta
7 steps How to prevent Thalassemia : Dr Sharda Jain & Vandana Gupta
Ā 
Circulatory Shock, types and stages, compensatory mechanisms
Circulatory Shock, types and stages, compensatory mechanismsCirculatory Shock, types and stages, compensatory mechanisms
Circulatory Shock, types and stages, compensatory mechanisms
Ā 
ANATOMY AND PHYSIOLOGY OF RESPIRATORY SYSTEM.pptx
ANATOMY AND PHYSIOLOGY OF RESPIRATORY SYSTEM.pptxANATOMY AND PHYSIOLOGY OF RESPIRATORY SYSTEM.pptx
ANATOMY AND PHYSIOLOGY OF RESPIRATORY SYSTEM.pptx
Ā 
ANATOMY AND PHYSIOLOGY OF REPRODUCTIVE SYSTEM.pptx
ANATOMY AND PHYSIOLOGY OF REPRODUCTIVE SYSTEM.pptxANATOMY AND PHYSIOLOGY OF REPRODUCTIVE SYSTEM.pptx
ANATOMY AND PHYSIOLOGY OF REPRODUCTIVE SYSTEM.pptx
Ā 
Call Girls in Lucknow Just Call šŸ‘‰šŸ‘‰8630512678 Top Class Call Girl Service Avai...
Call Girls in Lucknow Just Call šŸ‘‰šŸ‘‰8630512678 Top Class Call Girl Service Avai...Call Girls in Lucknow Just Call šŸ‘‰šŸ‘‰8630512678 Top Class Call Girl Service Avai...
Call Girls in Lucknow Just Call šŸ‘‰šŸ‘‰8630512678 Top Class Call Girl Service Avai...
Ā 
Chennai ā£ļø Call Girl 6378878445 Call Girls in Chennai Escort service book now
Chennai ā£ļø Call Girl 6378878445 Call Girls in Chennai Escort service book nowChennai ā£ļø Call Girl 6378878445 Call Girls in Chennai Escort service book now
Chennai ā£ļø Call Girl 6378878445 Call Girls in Chennai Escort service book now
Ā 
šŸ‘‰ Chennai Sexy Auntyā€™s WhatsApp Number šŸ‘‰šŸ“ž 7427069034 šŸ‘‰šŸ“ž JustšŸ“² Call Ruhi Colle...
šŸ‘‰ Chennai Sexy Auntyā€™s WhatsApp Number šŸ‘‰šŸ“ž 7427069034 šŸ‘‰šŸ“ž JustšŸ“² Call Ruhi Colle...šŸ‘‰ Chennai Sexy Auntyā€™s WhatsApp Number šŸ‘‰šŸ“ž 7427069034 šŸ‘‰šŸ“ž JustšŸ“² Call Ruhi Colle...
šŸ‘‰ Chennai Sexy Auntyā€™s WhatsApp Number šŸ‘‰šŸ“ž 7427069034 šŸ‘‰šŸ“ž JustšŸ“² Call Ruhi Colle...
Ā 
šŸ’ž Safe And Secure Call Girls CoimbatorešŸ§æ 6378878445 šŸ§æ High Class Coimbatore C...
šŸ’ž Safe And Secure Call Girls CoimbatorešŸ§æ 6378878445 šŸ§æ High Class Coimbatore C...šŸ’ž Safe And Secure Call Girls CoimbatorešŸ§æ 6378878445 šŸ§æ High Class Coimbatore C...
šŸ’ž Safe And Secure Call Girls CoimbatorešŸ§æ 6378878445 šŸ§æ High Class Coimbatore C...
Ā 
Lucknow Call Girls Just Call šŸ‘‰šŸ‘‰8630512678 Top Class Call Girl Service Available
Lucknow Call Girls Just Call šŸ‘‰šŸ‘‰8630512678 Top Class Call Girl Service AvailableLucknow Call Girls Just Call šŸ‘‰šŸ‘‰8630512678 Top Class Call Girl Service Available
Lucknow Call Girls Just Call šŸ‘‰šŸ‘‰8630512678 Top Class Call Girl Service Available
Ā 
Russian Call Girls In Pune šŸ‘‰ Just CALL ME: 9352988975 āœ…ā¤ļøšŸ’Ælow cost unlimited ...
Russian Call Girls In Pune šŸ‘‰ Just CALL ME: 9352988975 āœ…ā¤ļøšŸ’Ælow cost unlimited ...Russian Call Girls In Pune šŸ‘‰ Just CALL ME: 9352988975 āœ…ā¤ļøšŸ’Ælow cost unlimited ...
Russian Call Girls In Pune šŸ‘‰ Just CALL ME: 9352988975 āœ…ā¤ļøšŸ’Ælow cost unlimited ...
Ā 
Call girls Service Phullen / 9332606886 Genuine Call girls with real Photos a...
Call girls Service Phullen / 9332606886 Genuine Call girls with real Photos a...Call girls Service Phullen / 9332606886 Genuine Call girls with real Photos a...
Call girls Service Phullen / 9332606886 Genuine Call girls with real Photos a...
Ā 

4 u1.0-b978-1-4160-4224-2..50035-1..docpdf

  • 1. Chapter 32 Post-term Pregnancy Jamie L. Resnik, MD, and Robert Resnik, MD In 1902, Ballantyne1 described the problem of the post-term pregnancy screening examination performed between 17 and 22 weeksā€™ gestation for the ļ¬rst time in modern obstetric terms. Although the language was reported in one recent study to be more accurate in predicting the used to describe the entity in early 20th-century Scotland was different delivery date than a ļ¬rst-trimester screen,5 most reports have tended from that of today, Ballantyneā€™s words clearly reļ¬‚ected the thinking of to agree with the ļ¬ndings of Bennett and associates.6 These authors his time: ā€œThe postmature infant . . . has stayed too long in intrauterine randomly assigned women to either a ļ¬rst-trimester (n = 104) or a surroundings; he has remained so long in utero that his difļ¬culty is second-trimester (n = 92) ultrasound examination; 5 of the women in to be born with safety to himself and his mother. The problem of the ļ¬rst group underwent labor induction for a post-term gestation, the . . . postmature infant is intranatal.ā€ compared with 12 of those in the second group. In any case, it is clear During the ensuing years, the issue of post-term pregnancy, its that use of the LMP alone tends to substantially overestimate the risks, and its management generated great interest and controversy. An number of post-term gestations and that the widespread use of ļ¬rst- abundance of older as well as more recent data have ļ¬rmly established trimester ultrasound examinations, now used for noninvasive genetic that the fetal risk associated with a prolonged pregnancy is real, albeit screening, will have a great impact on the diagnosis and subsequent small. Consequently, the pregnancy that continues beyond 42 weeks management of this entity. requires careful surveillance. Pathogenesis Deļ¬nition and Incidence Knowledge of the mechanism of parturition is increasing rapidly, and By deļ¬nition, a term gestation is one that is completed in 37 to 42 the current understanding of the pertinent molecular, biochemical, weeks. Pregnancy is considered prolonged, or post-term, when it and physiologic ļ¬ndings are reviewed in Chapter 5. It is clear that the exceeds 294 days from the last menstrual period (LMP), or 42 weeks. normal timing of parturition requires the integration and synchrony The frequency of this occurrence has been reported to range from 4% of numerous factors, including the fetal hypothalamic-pituitary- to 14%, with only 2% to 7% of pregnancies completing 43 weeks. The adrenal axis, the placenta and its membranes, and the myometrium chances that parturition will occur precisely at 280 days after the ļ¬rst and cervix. Although it is not known speciļ¬cally why some pregnancies day of the LMP (40 weeks) is only 5%. are abnormally prolonged, clues exist from interesting observations of One of the major problems in delineating the extent of risk beyond aberrant timing of labor in humans and other species. For example, term is the limited reliability of the LMP as a basis for accurately pre- it has long been known that fetal pituitary defects in Holstein cattle dicting gestational age. Traditionally, and until the 1990s, most epide- may lead to failure of normal delivery timing.7 In humans, congenital miologic studies pertaining to fetal and neonatal risks of delayed primary fetal adrenal hypoplasia and placental sulfatase deļ¬ciency parturition were based on the LMP. Since that time, the use of ultra- leading to low estrogen production may result in delayed onset of labor sound, particularly in the ļ¬rst trimester, has led to much greater preci- and failure of normal cervical ripening.8,9 sion in pregnancy dating, and data conļ¬rm that the LMP is a much Whether the primary defect in delayed parturition involves aberra- less reliable predictor of true gestational age. For example, as early as tions in fetal endocrine signaling or abnormalities in the setting of the 1988, Boyd and colleagues2 showed that the incidence of post-term ā€œplacental clockā€ (as was suggested by McLean and colleagues10), or gestation fell from 7.5% when based on menstrual dating to 2.6% whether the myometrial contractile and cervical softening mechanisms when early ultrasound examination was used. In a subsequent study are at fault, it is clear from the abundant data currently available that by Gardosi and colleagues,3 the post-term delivery rate among women the timing of parturition is determined by complex interactions at the dated by LMP was 9.5% but decreased to 1.5% if ultrasound dating maternal-fetal interface. was used. In their study, 71.5% of ā€œpost-termā€ inductions as dated by LMP were not post-term according to ultrasound studies. This ļ¬nding is consistent with the observations of Taipale and Hiilesmaa,4 who performed ultrasound examinations at 8 to 16 weeksā€™ gestation in Risk Factors 17,221 women. When ultrasound biometric criteria rather than the Primiparity has long been known to be more frequently associated LMP were used to determine gestational age, the number of post-term with post-term gestation than multiparity. However, there also appears pregnancies fell from 10.3% to 2.7%. Although a second-trimester to be an increased frequency of recurrence among women who have
  • 2. 614 CHAPTER 32 Post-term Pregnancy had a previous post-term pregnancy. One large cohort study from 6 Denmark has demonstrated that women who delivered post-term in Stillbirth their ļ¬rst pregnancy had an almost threefold increase in the incidence Neonatal death of subsequent post-term pregnancy, compared with those whose ļ¬rst Postneonatal death delivery was at term.11 These ļ¬ndings were recently conļ¬rmed by 5 Kistka and coworkers12 in a study of 368,633 births in Missouri, in Mortality per 1000 ongoing pregnancies which mothers with an initial post-term birth were at increased risk for a subsequent post-term pregnancy (relative risk [RR], 1.88; 95% conļ¬dence interval [CI], 1.79 to 1.97). These ļ¬ndings also suggest the 4 possibility of a genetic predisposition, inasmuch as the risk of recur- rent post-term pregnancy in the Danish study was not observed if the ļ¬rst and second children had different fathers. 3 Perinatal Risks 2 Morbidity and Mortality Almost all reports up to the present time, even those with inherent limitations imposed by inaccuracies in gestational age determination, 1 suggest an increase in perinatal morbidity and mortality when preg- nancy goes beyond 42 weeksā€™ gestation. One of the earliest and most frequently cited studies was provided by the National Birthday Trust 0 of Britain in 1958, which undertook a detailed examination of more 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 than 17,000 births in the United Kingdom from March 3 to March 9 Gestational age (weeks) of that year.13 Their data demonstrated that the perinatal mortality rate began to increase after 42 weeksā€™ gestation, doubling by about 43 weeks, FIGURE 32-1 Perinatal mortality as a function of gestational age. and was four to six times higher at 44 weeks than at term. A more The rates of stillbirth, neonatal, and postneonatal death increase with advancing gestational age beyond 41 weeks. The perinatal mortality recent study showed that the risks begin to accelerate between 41 and is expressed per 1000 ongoing pregnancies. (From Hilder L, Costeloe 42 weeks and rise more sharply after that point (Fig. 32-1).14 Numerous K, Thilaganathan B: Prolonged pregnancy: Evaluating gestation- other reports have conļ¬rmed this increase in risk.15-17 Alexander and speciļ¬c risks of fetal and infant mortality. BJOG 1998;105:169-173.) associates18 retrospectively evaluated outcomes of more than 27,000 pregnancies with 41 or 42 weeksā€™ gestation, compared with approxi- mately 29,000 completed at 40 weeksā€™ gestation. Length of labor, inci- dence of prolonged second-stage labor, forceps use, and cesarean pared with term infants,17,23 and birth injuries can occur as a result of delivery were all increased with the longer gestation period. It is not difļ¬cult forceps deliveries and shoulder dystocia. Morbidity also clear, however, whether the observed increase in complications was due includes cephalohematomas, fractures, and brachial plexus palsy.24 to prolonged gestation, routine use of induction at 42 weeks, or Study of fetal growth characteristics in 7000 post-term infants con- both. ļ¬rmed a gradual shift toward higher birth weights and greater head In a more recent Norwegian study, in which 17,493 pregnancies circumference between 273 and 300 days of gestational age.25 These with conļ¬rmed dates by second-trimester ultrasound were analyzed, ļ¬ndings were further reinforced by a study of 519 pregnancies extend- 1336 were found to be post-term. The post-term group had twice the ing beyond 41 weeks, in which 23% of the newborns weighed more perinatal mortality rate (CI, 0.9 to 4.6); the RR of having an Apgar than 4000 g and 4% weighed more than 4500 g.26 score lower than 7 at 5 minutes was 2.0 (CI, 1.2 to 3.3), and the RR of Although the majority of post-term infants are appropriately grown requiring neonatal intensive care was 1.6 (CI, 1.3 to 2.0).19 Another or macrosomic, the risk of a small-for-gestational-age (SGA) infant is prospective cohort study of 27,514 pregnancies from the same country also increased in post-term pregnancy. In a population-based study of demonstrated that maternal and fetal risks were lowest at 39 weeksā€™ 510,029 singleton pregnancies from the Swedish Birth Registry, the rate gestation, with increasing rates of maternal and neonatal complica- of SGA infants increased from 2.2% in term infants to 3.8% in post- tions, as well as operative deliveries, as pregnancy proceeded past term infants.27 term.20 Similar ļ¬ndings were reported in a Danish population.21 Meconium Staining and Abnormal Fetal Growth Pulmonary Aspiration Since the report of Clifford22 and his description of the postmature- Almost all studies of post-term gestation report a markedly higher dysmature neonate with wasting of subcutaneous tissue, meconium incidence of meconium-stained amniotic ļ¬‚uid, compared with term staining, and peeling of skin, many have focused their attention on the pregnancies, and the greater risk of meconium aspiration syndrome in problems of the undernourished post-term fetus. In fact, only 10% to these infants is well recognized.17 Among those infants deļ¬ned by 20% of true post-term fetuses exhibit any of the ļ¬ndings described by ultrasound-estimated fetal growth curves to be appropriately sized for Clifford. Macrosomia is actually a far more common complication, gestational age (AGA), those delivered post-term had a threefold higher because, under most circumstances, the fetus continues to grow in incidence of meconium aspiration and twice the risk of an Apgar score utero. Twice as many post-term fetuses weigh more than 4000 g, com- of less than 4 at 5 minutes, compared with term AGA infants.27 The
  • 3. CHAPTER 32 Post-term Pregnancy 615 presence of oligohydramnios further complicates the risks of meco- However, a cohort study done in Sweden showed no correlation nium staining because of the lack of ļ¬‚uid to dilute the meconium, between an AFI of less than 5 cm and adverse outcome.38 Similarly, which results in thicker, more tenacious material in the oropharynx Divon and associates,39 in a longitudinal assessment of AFI in 139 and lower in the respiratory tract. women with post-term pregnancy, found an increased frequency of abnormal fetal heart rate tracings and meconium staining but no other signiļ¬cant adverse fetal outcome. Alļ¬revic and colleagues40 compared both methods with respect to pregnancy intervention in post-term Fetal Evaluation and pregnancies and found more frequent abnormal AFIs than abnormal Management vertical pocket depths, leading to more inductions and fetal monitor- ing but no difference in perinatal outcome. Morris and colleagues41 When one considers the rapidly accelerating risk of fetal morbidity and conducted a prospective, double-blinded, cohort study to determine mortality between 42 and 43 weeksā€™ gestation and again between 43 whether an AFI of less than 5 cm or a single vertical pocket of less than and 44 weeksā€™ gestation (see Fig. 32-1), it becomes apparent that no 2 cm was superior in predicting adverse perinatal events. They found historically derived or laboratory-measured fetal age provides the pre- the AFI to be signiļ¬cantly more associated with birth asphyxia and cision required in the management of the post-term pregnancy. Tra- meconium aspiration, but with poor sensitivity. More recently, Zhang ditional landmarks, such as LMP, uterine size, and ļ¬rst auscultation of and associates,42 using data from the Routine Antenatal Diagnostic fetal heart tones, can miscalculate gestational age by 2 weeks or more. Imaging with Ultrasound (RADIUS) study, compared a large popula- Even sensitive sonographic determinations, such as crown-to-rump tion of women screened by ultrasound to control subjects and observed length in the ļ¬rst trimester, demonstrate a range of several days. In that women with isolated oligohydramnios had no greater adverse fact, in any given gestation, the actual fetal age is known only if the perinatal events or impaired growth. Another study comparing the two time of ovulation and conception have been studied, as in ovulation techniques showed that the single vertical pocket method used for induction and in vitro fertilization. Therefore, a gravida thought to be antepartum surveillance led to less frequent diagnosis and intervention at 41 to 42 weeks or further in gestation, in current practice, either for oligohydramnios, but without any difference in adverse perinatal is induced and delivered or undergoes meticulous antenatal outcomes.43 monitoring. Given these disparate ļ¬ndings, it is not difļ¬cult to understand why there is no consensus as to the reliability or superiority of either tech- nique for identiļ¬cation of the fetus at risk in prolonged pregnancy. Antenatal Fetal Monitoring Therefore, it is reasonable to conclude that an AFI of less than 5 cm, Despite the lack of randomized clinical trials, it is generally accepted particularly if it has been falling sharply over a short time interval, or that careful antepartum and intrapartum fetal monitoring can virtu- the absence of a single identiļ¬able vertical pocket of greater than 2 cm, ally eliminate fetal post-term mortality and reduce fetal morbidity.28-32 indicates that delivery is warranted. Conversely, it is also reasonable to However, a careful evidence-based literature analysis concluded that consider that the ļ¬nding of a normal amniotic ļ¬‚uid volume implies data were insufļ¬cient to determine whether routine antenatal surveil- little fetal risk. lance before 41 weeksā€™ gestation improves outcome or which type of There does not appear to be any value in monitoring Doppler ļ¬‚ow monitoring and frequency are most appropriate.33 Consequently, most velocity in fetal vessels, inasmuch as there is no correlation between obstetricians initiate antenatal testing at 41 weeksā€™ gestation and repeat the ļ¬ndings and outcome.44 Zimmerman and associates45 demon- the testing twice weekly. This testing consists of either a biophysical strated that the sensitivity of umbilical artery velocimetry for predict- proļ¬le (BPP) or a nonstress test and assessment of amniotic ļ¬‚uid ing poor outcome was 7%. volume. In a study of 307 women whose pregnancies had proceeded beyond 294 days, a normal twice-weekly BPP that included normal amniotic Fetal Monitoring versus ļ¬‚uid volume resulted in no perinatal mortalities, and morbidity was Induction of Labor equivalent to that observed in a comparison group undergoing elective Even though antenatal monitoring can virtually eliminate perinatal labor induction with a favorable cervix.32 Based on a cumulative expe- mortality in the post-term gestation, some morbidityā€”including rience with 19,221 high-risk pregnancies, the same investigative group meconium staining, increased cesarean delivery for a diagnosis of fetal recommended delivery if amniotic ļ¬‚uid volume decreases.34 distress, and macrosomia with its associated complicationsā€”still The technique used to assess amniotic ļ¬‚uid volume and its role in exists. Although the frequency of morbid events is very low, the evaluation of the prolonged gestation remains controversial because of continuing concern has been addressed by an alternative approachā€” conļ¬‚icting studies regarding which of the two tests of volume (amni- that of cervical ripening followed by induction at 41 or 42 weeksā€™ otic ļ¬‚uid index [AFI] or single vertical pocket) is the better predictor gestation. of outcome and the possibility that the AFI may lead to too many Comparison of these two management approaches in several ran- unnecessary interventions. Oligohydramnios is thought to be a marker domized controlled trials has yielded generally similar results. Hannah for fetal complications, including umbilical cord compresssion, hypox- and coauthors46 studied 3407 women with uncomplicated pregnancies emia, and meconium aspiration, as well as fetal heart rate abnormali- at 41 or more weeksā€™ duration, who were randomly assigned to ties and risk of neonatal admission to an intensive care unit.35-37 either elective induction after cervical ripening with prostaglandin E2 Bochner and coworkers36 observed an almost 24-fold increase in cesar- (PGE2) gel or serial antenatal monitoring (fetal kicks, nonstress test, ean delivery for the indication of fetal distress when the maximum amniotic ļ¬‚uid). In the monitored group, labor was induced only if vertical amniotic ļ¬‚uid pocket depth was less than 3 cm. The incidence there was evidence of compromised fetal status. The authors observed of meconium-stained amniotic ļ¬‚uid in the post-term gestation was a lower rate of cesarean delivery for a diagnosis of fetal distress in the 37% among those women with adequate amniotic ļ¬‚uid volume but induction group but no signiļ¬cant difference between the two groups increased to 71% if the amniotic ļ¬‚uid volume was decreased.31 in fetal mortality or morbidity. The same investigators subsequently
  • 4. 616 CHAPTER 32 Post-term Pregnancy reported that routine induction was more cost-effective than serial including a signiļ¬cant risk of postpartum hemorrhage and an increased antenatal monitoring.47 The Maternal-Fetal Medicine Network pro- risk of cesarean delivery. spectively evaluated 440 patients, comparing induction with serial The Bishop score,53 or some suitable modiļ¬cation of it, can be used monitoring.48 They observed no fetal deaths in either group, and rates as a guide to select the most appropriate induction technique. This is of neonatal morbidity and cesarean delivery were similar. A more especially true in primigravid women. If the Bishop score is lower than recent study from Norway, in which 254 women at 41 weeksā€™ gestation 5, amniotomy and oxytocin infusion are associated with an unaccept- were randomly assigned to an induction or expectant manage- ably high incidence of unsuccessful inductions as well as fetal and ment group, found no differences in neonatal outcomes or mode of maternal complications.54 In these circumstances, cervical ripening delivery.49 should be undertaken before uterine contractions are provoked. Given These combined trials have led to the conclusion that neither the rapidly increasing use of transvaginal ultrasound (TVUS) to assess approach has a substantive advantage over the other. A small advantage cervical length and dilatation and its usefulness in the diagnosis of to the induction approach was suggested by the recent Cochrane preterm labor, it is not unreasonable to apply this technology to cervi- Review of 19 studies, which determined that a policy of labor induc- cal assessment in post-term pregnancy. One study of 240 women, tion at 41 weeks resulted in fewer fetal deaths, although the differences comparing TVUS with digital cervical examination using receiver and absolute risk were extremely small (1 in 2986 versus 9 in 2953; operating characteristic (ROC) curves, demonstrated that a cervical odds ratio, 0.3; CI, 0.9 to 0.99). There was no signiļ¬cant difference in length of 28 mm was a better predictor of induction success (vaginal the cesarean section rate.50 delivery within 24 hours) than the Bishop score.55 However, conļ¬‚icting Nevertheless, in terms of physician preferences in the United States, ļ¬ndings were reported by Chandra and associates.56 induction at 41 weeks has become the mode of practice and the debate The most frequently used current cervical ripening techniques moot. A recent survey of 1000 randomly selected members of the include chemical agents such as PGE2 (dinoprostone, trade names American College of Obstetricians and Gynecologists revealed that Prepidil and Cervidil Rx), administered vaginally or intracervically, 73% routinely induce low-risk women at 41 weeks. For women who and misoprostol (Cytotec Rx), administered vaginally or orally. Both decline induction, approximately 65% of physicians initiate antenatal appear to be effective in improving the Bishop score and to result in testing twice weekly at 41 weeks.51 It is clear that medical induction shorter labor times and possibly fewer failed inductions. Misoprostol, rates have increased sharply in the United States. Between 1980 and in doses of 25 Ī¼g given vaginally every 4 hours, appears to be slightly 1996, the rate of induction doubled (from 12.9% to 25.8%), the most more effective that dinoprostone but is associated with a higher fre- common indication being that of the post-term pregnancy.52 quency of uterine tachysystole. A recent review of randomized trials performed between 1987 and 2005 compared the two agents and con- ļ¬rmed that misoprostol was superior to dinoprostone at any dose and Management Summary route of administration in terms of achieving vaginal delivery within It seems appropriate to recommend the following steps to evaluate and 24 hours. There was no difference in the rate of cesarean delivery.57 manage the post-term gestation: This study conļ¬rmed an earlier Cochrane database review which con- cluded that the use of vaginal misoprostol is more effective than con- 1. Although there is insufļ¬cient evidence because of the low-risk ventional methods of cervical ripening and labor induction. Compared nature of either approach, current obstetric practice dictates that with placebo, oxytocin, or intracervical or vaginal PGE2, misoprostol labor induction be offered between 41 and 42 weeksā€™ gestation in resulted in increased cervical ripening, decreased use of oxytocin, and the presence of a favorable cervix. increased rates of vaginal delivery. However, misoprostol also caused 2. If the cervix is unfavorable, alternate approaches include either an increased rate of uterine hyperstimulation.58 cervical ripening followed by induction of labor or twice-weekly Vaginal inserts such as balloon catheters also have their advocates fetal monitoring. Delivery should be accomplished promptly if for cervical ripening. A systematic review concluded that these mechan- there is evidence of fetal compromise. ical dilators do not compare favorably with chemical inducing agents 3. It is prudent to use the BPP, or some modiļ¬cation of the BPP, to in terms of delivery success rates but are associated with less uterine determine antenatal fetal condition. hypercontactility.59 Methods of Labor Induction Developmental Effects of The issue of labor induction and cervical ripening agents is addressed in detail in Chapter 36 and is summarized brieļ¬‚y here. Post-term Gestation Because normal labor depends on efļ¬cient myometrial contrac- Studies on the development of children from prolonged pregnancies tions acting on a compliant cervix to efface and dilate it, methods of are difļ¬cult to evaluate because investigators have not separated neo- labor induction must take into account both components of the uterus. nates asphyxiated in utero and growth-restricted (dysmature) post- If the cervix is already soft, effaced, and partially dilated, intravenous term neonates from otherwise normally born neonates. A study of infusion of oxytocin may be sufļ¬cient to stimulate contractions. Con- neonatal behavior among 106 dysmature infants revealed an increased ventional practice requires amniotomy to be performed as a ļ¬rst step, number of illnesses and sleep disorders as well as diminished social because this procedure maximizes the effectiveness of oxytocin. If the competence during the ļ¬rst year of life (Vineland Social Maturity cervix is unripe, oxytocin will not cause it to ripen, and amniotomy Scale). Also, and not unexpectedly, the incidence of fetal distress was is inappropriate. Although labor contractions can be stimulated by high, and those babies who were asphyxiated in utero had a higher oxytocin, such a result is futile, because many hours of such contrac- incidence of abnormal neurologic signs in the neonatal period.60 All tions are required to produce any sort of change in the cervix, and the infants had signs of desquamation of skin and wasting of subcutaneous ensuing prolonged labor can lead to an increase in obstetric morbidity, tissue, however, and the group of children studied was not compared
  • 5. CHAPTER 32 Post-term Pregnancy 617 with any post-term children who did not have these physical ļ¬ndings 14. Hilder L, Costeloe K, Thilaganathan B: Prolonged pregnancy: Evaluating at birth. gestation-speciļ¬c risks of fetal and infant mortality. BJOG 105:169-173, Field and coworkers61 studied a group of 40 dysmature offspring, 1998. all of whom had parchment-like skin and long, thin bodies. At birth, 15. Nakano R: Post-term pregnancy: A ļ¬ve year review from Osaka National Hospital. Acta Obstet Gynecol Scand 51:217, 1972. their Brazelton interaction and motor scores were lower than in 16. Sachs BP, Friedman EA: Results of an epidemiological study of post-date term controls, and at 4 months they scored lower on the Denver pregnancy. J Reprod Med 31:162, 1986. Developmental Scale. By 8 months, the Bayley motor scores of the 17. Eden R, Seifert L, Winegar A, et al: Perinatal characteristics of uncompli- post-term subjects were equivalent to those of control infants, but their cated post-date pregnancies. Obstet Gynecol 69:296, 1987. mental scores were slightly lower. This study differed in at least one 18. Alexander JM, McIntire DD, Leveno UJ: Forty weeks and beyond: signiļ¬cant way from that of Lovell60: The Apgar scores at 5 minutes in Pregnancy outcomes by week of gestation. Obstet Gynecol 96:291, 2000. the two groups were identical, thus partially correcting for in utero 19. Nakling J, Backe B: Pregnancy risk increases from 41 weeks of gestation. asphyxia. Acta Obstet Gynecol 85:663-668, 2006. In a large retrospective review, Zwerdling23 observed that post-term 20. Heimstad R, Romundstad PR, Eik-Nes SH, et al: Outcomes of pregnancies infants weighing less than 2500 g had a neonatal mortality rate seven beyond 37 weeks of gestation. Obstet Gynecol 108:500-508, 2006. 21. Olesen AW, Westergaard JG, Olsen J: Perinatal and maternal complications times that of post-term infants as a whole. This ļ¬nding conļ¬rmed the related to post-term delivery: A national regiser-based study, 1978-1993. additional risk of the dysmature growth pattern in some post-term Am J Obstet Gynecol 189:222-227, 2003. infants. The increased mortality rate was observed up to 2 years of age, 22. Clifford SH: Postmaturityā€”with placental dysfunction. J Pediatr 44:1, 1954. but at 5 years the data on growth and intelligence in Zwerdlingā€™s study 23. Zwerdling MA: Factors pertaining to prolonged pregnancy and its outcome. population revealed no differences between prolonged-gestation and Pediatrics 40:202, 1967. normal-gestation children. These ļ¬ndings were conļ¬rmed in a pro- 24. Usher RH, Boyd ME, McLean FH, et al: Assessment of fetal risk in post-date spective study in which 129 children born of prolonged pregnancy pregnancies. Am J Obstet Gynecol 158:259, 1988. were compared with 184 term controls.62 At 1 year and again at 2 years 25. McLean FH, Boyd ME, Usher RH: Post-term infants: Too big or too small? of age, there were no differences between the two groups with respect Am J Obstet Gynecol 164:619, 1991. to intelligence scores, physical milestones, or intercurrent illnesses. 26. Pollack RN, Hauer-Pollack G, Divon MY: Macrosomia in post-dates preg- nancy: The accuracy of routine ultrasonographic screening. Am J Obstet One recent cohort study from Denmark linked hospital records of Gynecol 167:7, 1992. 277,435 pregnancies delivering at term or beyond to cases of childhood 27. Clausson B, Cnattingius S, Axelsson O: Outcomes of post-term births: The epilepsy. The researchers found a slight increase in the incidence of role of fetal growth restriction and malformations. Obstet Gynecol 94:758, epilepsy as a function of gestational age at or after 43 weeks, but only 1999. among those infants delivered by cesarean section or other operative 28. Hauth JC, Goodman MT, Gilstrap LC III, et al: Post-term pregnancy. delivery.63 The risk was not observed after 1 year of life. Whether this J Obstet Gynecol 56:467, 1980. ļ¬nding reļ¬‚ects a problem unique to advanced gestational age or com- 29. Freeman RK, Garite TJ, Modanlou H, et al: Postdate pregnancy: Utilization plications that required expedient delivery is unclear. of contraction stress testing for primary fetal surveillance. Am J Obstet Gynecol 140:128, 1981. 30. Eden R, Gergely RZ, Schifrin BS, et al: Comparison of antepartum testing schemes for the management of the postdate pregnancy. Am J Obstet References Gynecol 144:683, 1982. 1. Ballantyne JW: The problem of the postmature infant. J Obstet Gynaecol 31. Phelan JP, Platt LP, Yeh S-Y, et al: The role of ultrasound assessment of Br Emp 2:36, 1902. amniotic ļ¬‚uid volume in the management of the post-date pregnancy. Am 2. Boyd ME, Usher RH, McLean FH, et al: Obstetric consequences of post- J Obstet Gynecol 151:304, 1984. maturity. Am J Obstet Gynecol 158:334, 1988. 32. Johnson JM, Harman CR, Lange IR, et al: Biophysical proļ¬le scoring in the 3. Gardosi J, Vanner T, Francis A: Gestational age and induction of labour for management of the post-term pregnancy. Am J Obstet Gynecol 154:269, prolonged pregnancy. BJOG 104:792, 1997. 1986. 4. Taipale P, Hiilesmaa V: Predicting delivery date by ultrasound and last 33. American College of Obstetricians and Gynecologists: ACOG Practice Pat- menstrual period on early gestation. Obstet Gynecol 97:189, 2001. terns: Management of Post-term Gestation. Practice Bulletin No. 55. Wash- 5. Olesen AW, Thomsen SG: Prediction of delivery date by sonography in ington, DC, ACOG, 2004. the ļ¬rst and second trimesters. Ultrasound Obstet Gynecol 28:292-297, 34. Manning FA, Morrison I, Harman CR, et al: Fetal assessment based on fetal 2006. biophysical proļ¬le scoring: Experience in 19,221 referred high risk preg- 6. Bennett KA, Crane JM, Oā€™Shea P, et al: First trimester ultrasound screening nancies. II: An analysis of false negative deaths. Am J Obstet Gynecol is effective in reducing post-term labor induction rates: A randomized 157:880, 1987. controlled trial. Am J Obstet Gynecol 190:1077-1081, 2004. 35. Leveno KJ, Quirk JG, Cunningham FG, et al: Prolonged pregnancy: I. 7. Holm LW: Prolonged pregnancy. Adv Vet Sci 11:159, 1967. Observations concerning the causes of fetal distress. Am J Obstet Gynecol 8. France JT, Liggins GC: Placenta sulfatase deļ¬ciency. J Clin Endocrinol 150:465, 1984. 29:138, 1969. 36. Bochner CJ, Medearis Al, Davis J, et al: Antepartum predictors of fetal dis- 9. Fliegner JRH, Schindler I, Brown JB: Low urinary oestriol excretion during tress in post-term pregnancy. Am J Obstet Gynecol 157:353, 1987. pregnancy associated with placental sulphatase deļ¬ciency or congenital 37. Tongsong T, Srisomboon J: Amniotic ļ¬‚uid volume as a predictor of fetal adrenal hypoplasia. J Obstet Gynaecol Br Commonw 79:810, 1972. distress in post-term pregnancy. Int J Gynaecol Obstet 40:213, 1993. 10. McLean M, Bisits S, Davies J, et al: A placental clock controlling the length 38. Montan S, Malcus P: Amniotic ļ¬‚uid index in prolonged pregnancy. of human pregnancy. Nat Med 1:460-463, 1995. J Matern Fetal Invest 5:4, 1995. 11. Olesen AW, Basso O, Olsen J: Risk of recurrence of prolonged pregnancy. 39. Divon M, Marks AD, Henderson CE: Longitudinal measurement of amni- BMJ 326:476, 2003. otic ļ¬‚uid index in post-term pregnancies and its association with fetal 12. Kistka ZA, Palomar L, Boslaugh SE, et al: Risk for posttterm delivery after outcome. Am J Obstet Gynecol 172:142, 1995. previous posttterm delivery. Am J Obstet Gynecol 196:241.e1-6, 2007. 40. Alļ¬revic Z, Luckas M, Walkinshaw SA, et al: A randomized comparison 13. Butler NR, Alberman ED: The Second Report of the 1958 British Perinatal between amniotic ļ¬‚uid index and maximum pool depth in the monitoring Mortality Survey. Edinburgh, E & S Livingstone, 1969, p 327. of post-term pregnancy. BJOG 104:207, 1997.
  • 6. 618 CHAPTER 32 Post-term Pregnancy 41. Morris JM, Thompson K, Smithey J, et al: The usefulness of ultrasound 52. Yawn BP, Wollan P, McKeon K, et al: Temporal changes in rates and reasons assessment of amniotic ļ¬‚uid in predicting adverse outcome in prolonged for medical induction of term labor, 1980-1996. Am J Obstet Gynecol pregnancy: A prospective blinded observational study. BJOG 110:989-994, 184:611, 2001. 2003. 53. Bishop EH: Pelvic scoring for elective induction. Obstet Gynecol 24:266, 42. Zhang J, Troendle J, Meikle S, et al: Isolated oligohydramnios is not associ- 1964. ated with adverse pregnancy outcome. BJOG 111:220-225, 2004. 54. Calder AA, Greer CA: Cervical physiology and induction of labor. In 43. Chauhan SP, Doherty DD, Magann EF, et al: Amniotic ļ¬‚uid index vs single Bonnar J (ed): Recent Advances in Obstetrics and Gynecology 17. Edin- deepest pocket technique during modiļ¬ed biophysical proļ¬le: A random- burgh, Churchill Livingstone, 1992. ized clinical trial. Am J Obstet Gynecol 191:661-667, 2004. 55. Pandis GU, Papageorghiou AJ, Ramanathan JG, et al: Preinduction sono- 44. Guidetti DA, Divon MY, Cavalieri RL, et al: Fetal umbilical artery ļ¬‚ow graphic measurement of cervical length in the prediction of successful velocimetry in post-date pregnancies. Am J Obstet Gynecol 157:1521, induction of labor. Ultrasound Obstet Gynecol 18:623, 2001. 1987. 56. Chandra S, Crane JMG, Hutchens D, et al: Transvaginal ultrasound and 45. Zimmerman P, Alback T, Koskinen J, et al: Doppler ļ¬‚ow velocimetry of the digital examination in predicting successful labor induction. Obstet Gynecol umbilical artery, uteroplacental arteries and fetal middle cerebral artery in 98:2, 2001. prolonged pregnancy. Ultrasound Obstet Gynecol 5:189, 1995. 57. Crane JM, Butler B, Young DC, et al: Misoprostol compared with prosta- 46. Hannah ME, Hannah WJ, Hellmann J, et al: Induction of labor as compared glandin E2 for labour induction in women at term with intact membranes with serial antenatal monitoring in post-term pregnancy. N Engl J Med and unfavourable cervix: A systematic review. BJOG 113:1366-1376, 326:1587, 1992. 2006. 47. Goeree R, Hannah ME, Hweson S: Cost-effectiveness of induction of labor 58. Hofmeyr GJ, Gulmezoglu AM: Vaginal misoprostol for cervical ripening versus serial antenatal monitoring in the Canadian Multicentre Post-term and induction of labour. Cochrane Database Syst Rev (1):CD000941, Pregnancy Trial. Canadian Med Assoc 152:1445, 1995. 2003. 48. National Institute of Child Health and Development (NICHD) Network of 59. Boulvain M, Kelly A, Lohse C, et al: Mechanical methods for induction of Maternal-Fetal Medicine Unit: A clinical trial of induction of labor versus labour. Cochrane Database Syst Rev (4):CD000941, 2002. expectant management in post-term pregnancy. Am J Obstet Gynecol 60. Lovell KE: The effect of postmaturity on the developing child. Med J Austr 170:716, 1994. 1:13, 1973. 49. Heimstad R, Skogvoll E, Mattsson L-A, et al: Induction of labor or serial 61. Field TM, Dabiri C, Hallock N, et al: Developmental effects of prolonged antenatal fetal monitoring in the post-term pregnancy: A randomized con- pregnancy in the postmaturity syndrome. J Pediatr 90:836, 1977. trolled trial. Obstet Gynecol 109:609-617, 2007. 62. Shime J, Librach CL, Gare DJ, et al: The inļ¬‚uence of prolonged pregnancy 50. Gulmezoglu AM, Crowther CA, Middleton P: Induction of labour for on infant development at one and two years of age: A prospective controlled improving birth outcomes for women at or beyond term. Cochrane Data- study. Am J Obstet Gynecol 154:341, 1986. base Syst Rev (4):CD004945, 2006. 63. Ehrenstein V, Pedersen L, Holsteen V, et al: Postterm delivery and risk for 51. Cleary-Goldman J, Bettes B, Robinson JN, et al: Post-term pregnancy: Prac- epilepsy in childhood. Pediatrics 119:554-561, 2007. tice patterns of contemporary obstetricians and gynecologists. Am J Peri- natol 23:15-20, 2006.