Antepartum cause of fetal deaths Asphyxia (intrauterine growth restriction [IUGR], prolonged gestation)… attributed to 30% of antepartum fetal deaths Maternal complications (placental abruption, hypertension, preeclampsia, Rh isoimmunization and diabetes mellitus)……. attributed to 30% of antepartum fetal deaths Congenital malformations and chromosome abnormalities….. attributed to 15% of antepartum fetal deaths 5% to infection At least 20% of fetal deaths have no obvious etiology.

1. POST TERM
PREGNANCY
By Dr. Wondu
Belayneh
April 2021

2. Definitions:
 Postterm pregnancy as a gestation that has completed or
gone beyond 42, weeks or 294 days, from the first day of
the last menstrual period (LMP). (ACOG, FIGO & WHO)
 Many terms have been used in the past, including postmature,
postdates, prolonged, and postterm.
 Pregnancies are now designated to be
Early term 37 0/7 to 38 6/7 weeks.
Full term 39 0/7 to 40 6/7 weeks.
Late term 41 0/7 to 416/7 weeks.
Postterm 420/7 weeks and beyond.

3. Incidence:
 The incidence of Postterm pregnancy is 5.5 percent
 When GA confirmed by LNMP& early US ≤2%

4. Etiology
 Mostly unknown.
 Error in menstrual dating (GA estimation ).
 poor recall by the patient or
 physiologic variations in the duration of follicular
phase(delayed ovulation).
 Fetal factors: Anencephaly, male sex
 Placental factor: sulfatase deficiency
 Maternal factors: Primigravida, past prolonged
pregnancy, elderly

5. Risk Factors
 Primigravidity
 Prior postterm pregnancy: recurrence after 1posterm is 2
to 3-fold; after two prior postterm pregnancies, 4 fold
 Male fetus
 Maternal obesity
 Older maternal age
 Genetic predisposition: mother who themselves postterm,
twin female

6. Risk Factors
 Rare causes of post term pregnancy include
Anencephaly
Congenital primary fetal adrenal hypoplasia
Deficiency of placental sulfatase

7. Diagnosis
 The diagnosis of postterm is based on accurate
gestational dating.
 The three most commonly used methods: LNMP,
timing of intercourse and early ultrasound
assessment.
 Combination of ultrasound with LMP is superior to
the use of the LMP alone.
 The gestational age is most accurate if the
crown-rump length is measured in the first trimester
with an error of ± 5 to 7 days.

8. Diagnosis
 The gestational age is most accurate if the
crown-rump length is measured in the first trimester
with an error of ± 5 to 7 days.
 Error of US dating:
* up to 22 weeks -------- ± 7days
* 22to 30 weeks --------- ± 14 day
* beyond 30 weeks ------- ± 21days

9. RISKS TO THE FETUS AND THE MOTHER
• Post term pregnancy is associated with
significant risks to the fetus as well as to
the mother

10. Perinatal Mortality
• The risk of perinatal mortality (PNMR) increases as gestational
age advances beyond the EDD.
• After reaching a nadir at 39 - 40 wks, the PNMR increased as
pregnancy exceeded 41 weeks.
• A significant increase in fetal mortality was detected from 41
weeks’ gestation onward (1.5X, 1.8X, and 2.9X at 41, 42, and 43
weeks, respectively)
• Predictors of perinatal mortality in post-term pregnancy are:
LBW (5.7x) and maternal age 35 years or greater (1.88x)
• Macrosomia was associated with a modest protective effect for
perinatal death (RR, 0.51)

11. Postmaturity Syndrome
Features include
 wrinkled, patchy, peeling skin;
 long, thin body suggesting
wasting;
 advanced maturity i.e open-eyed,
unusually alert,& appears old and
worried.
 The nails are typically long.
 10 % of pregnancies b/n 41 and 43
weeks. 33 % at 44 weeks
 Associated oligohydramnios
increases the likelihood of
postmaturity Postmature infant delivered at 43 wks'
gestation. Thick, viscous meconium
coated the desquamating skin.

12. • are at increased risk of umbilical cord
compression due to oligohydramnios
• meconium aspiration
• increased FHR abnormalities
• short-term neonatal complications
 hypoglycemia
 seizures
respiratory insufficiency
• long-term neurologic sequelae.

13. Dysmaturity (postmaturity syndrome)
 Stage 1 - alert facial expression; recent weight loss
with decreased subcutaneous fat and muscle mass
 Stage 2 - green meconium staining of skin and
umbilicus, wrinkled skin
 Stage 3 - yellow staining of nails, skin and umbilicus
indicative of prolonged passage of meconium

14. Fetal Distress and Oligohydramnios
• Cord compression associated with
oligohydramnios may lead to an increased
incidence of "fetal distress" during labor
• meconium release into an already reduced
amnionic fluid volume causes thick, viscous
meconium that may cause meconium aspiration
syndrome

15. Macrosomia
• Postterm infants tend to be larger than term
infants
• Birthweight ≥ 4000 g; 8.5 % at 37 to 41 wks
and 11.2 % at ≥ 42 wks
• Complications of macrosomia include prolonged
labor, cephalopelvic disproportion, and shoulder
dystocia, all of which increase the risk of birth
injury

16. Other risks
• Fetal-Growth Restriction
• Uteroplacental insufficiency
• Meconium aspiration
• Asphyxia before, during and after delivery
• Fractures and Peripheral nerve injury
• Pneumonia
• Septicaemia
• Intra cranial hemorrhage
• Still birth rate increases significantly at term with
advancing gestation.

17. Maternal risks include
Anxiety
Prolonged labor (> 24 hours)
Dystocia
Operative vaginal delivery
Severe perineal injury (third- or fourth-degree laceration)
Increased C/S delivery .
 PPH
Puerperal infection: chorioamnionitis, endomyometritis

18. MANAGEMENT
 Confirm GA
 Review the perinatal case document
 Physical examination to
 EFW, ascertain viability
 Assess the adequacy of the pelvis & bishop’s score
 Options of mgt
 Expectant
 Direct termination

19. Termination
• 42wks + favorable Cx – direct induction
• 42wks + unfavorable Cx – induce after ripening

20. Timing of Delivery in Multiple Gestations
 Given consistent evidence of increased risk in twin
pregnancies that extend past 38 to 39 weeks’ gestation
(analogous to a postdate singleton gestation),
 Recommended timing of delivery in multiple
gestations
at 38 weeks for uncomplicated dichorionic gestations
between 34 and 376/7 weeks for uncomplicated
monochorionic diamniotic twins.
uncomplicated triplets anytime between 35 and 36
weeks.

21. Intrapartum Management
• Labor is a particularly dangerous time for the
postterm fetus
• Labor follow up
• Identification of thick meconium
• if the depressed newborn has meconium-
stained fluid, then intubation is done with
tracheal suctioning

22. PREVENTION
Some interventions have been suggested to decrease
the incidence of post term pregnancy.
1. Accurate dating based on early U/S
↓ed the incidence by 70% & so minimized
unnecessary intervention.
2. Manual nipple stimulation at term , may promote
labour at term
3. Sweeping of the membranes at or near term

23. Prevention:
Some interventions have been suggested to decrease the incidence
of post term pregnancy.
Recording LMP and calculating EDD at the time of first ANC
visit.
Routine early ultrasound for dating of pregnancy: ↓ed the
incidence by 70% & so minimized unnecessary intervention.
Review of antenatal card and ultra sonographic reports in terms of
fetal growth.
Sweeping of membranes from 38 wks onwards decreases number
of pregnancies going beyond 41 and 42 wks.
As soon as prematurity is ruled out in high risk cases induction of
labor will prevent post maturity.

24. Thank you