Post term pregnancy has increased maternal and perinatal adverse outcomes.

1. Post-term pregnancy
Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics, Mekelle
UniversityCollege of Health Sciences)

2. OUTLINE
• DEFINITION
• PREVALENCE
• ETIOLOGY
• RISK FACTORS
• DIAGNOSIS
• MORBIDITY AND MORTALITY
• MANAGEMENT
• RECURRENCE RISK
• PREVENTION
2
Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

3. DEFINITION
• Postterm pregnancy is a gestation that has completed or gone beyond 42 weeks or
294 days from the first day of the last menstrual period .(ACOG,FIGO,WHO)
• Cuttoff 42 weeks has been taken = increased risk of fetal death at 42 weeks and
beyond.(early studies )
• Gestational age that warrants clinical concern should be 41 weeks.(more recent
perinatal mortality data)
• The timely onset of labor is an important determinant of perinatal outcome.
3
Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

4. Cont...
• Confusion regarding proper terminology;
 postmature, postdates, prolonged, postterm
• Recently ACOG and SMFM have endorsed the terms below which designate
gestational ages at higher risk & reduce confusion
●Postterm – ≥42+0 weeks of gestation
●Late term – 41+0 to 41+6 weeks of gestation.
●Full term – 39+0 to 40+6 weeks of gestation.
●Early term – 37+0 to 38+6 weeks of gestation.
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

5. PREVALENCE
• Vary depending on the population studied.
• 0.4% (Austria) - 7% to 8% ( Denmark, Sweden)
• These differences in incidences are the result of;
(1) different approaches for managing pregnancies beyond the EDD
(2) different criteria for gestational age dating
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

6. ETIOLOGY
Mostly unknown
Maternal or fetal genetic influence on the initiation of parturition
 Defects in fetal production of hormones involved in parturition(rare)
e.g, placental sulfatase deficiency, Anencephaly
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

7. RISK FACTORS
Previous postterm.............highest risk (RR ≥2)
Nulliparity
Male fetus
Obesity
Older maternal age modest risk factors ( RR <2)
 Personal history of postterm birth
Maternal ancestry (race)
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

8. DIAGNOSIS
• Is based on accurate gestational dating(EDD)
• Commonly used methods to determine the EDD
1. Knowledge of the date of the LMP,
2. Timing of intercourse or embryo transfer, and
3. Early ultrasound assessment.
• Other methods —uterine size, quickening, ability to detect fetal heart
tones by Doptone, and fundal height measurement—not common
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

9. 1. knowledge of the date of the LMP
• Assumes that conception occurs on the 14th day of the menstrual cycle.
• The timing of ovulation varies between an individual’s menstrual cycles and
between individuals
• Overestimation of gestational age, and may result in a higher frequency of
induction of labor for presumed postterm pregnancy.
• Even with exactly recalled menstrual dates, there still is imprecision, and first-
trimester sonography is the most accurate method to establish or confirm
gestational age (ACOG, 2020b).
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

10. 2. Pregnancies Concived by Assisted Reproduction
• Fresh in vitro fertilization cycle
EDD=date of egg retrieval/fertilization + 266 days
• In a cycle using a frozen cleavage stage embryo (day 3 embryo)
EDD = date of embryo transfer + 263 days
• In a cycle using a frozen blastocyst stage embryo (day 5 embryo)
EDD =date of embryo transfer + 261 days
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

11. 3. Early ultrasound assessment
• Superior to the use of LMP alone.
• The EDD is most accurately determined = First TMX CRL measurment ( ± 5/7
days)
• The EDD is considered suboptimally dated if not confirmed by an ultrasound
before 22 weeks.
• For twin pregnancies, if there is a discrepancy between the twins in biometric
measurements, the EDD should be based on the measurements for the larger twin(
consensus)
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

12. Reassigning EDD based on LMP date-ultrasound discrepancy
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

13. MORBIDITY AND MORTALITY
Many of the complications are
sequelae of either excessive fetal
growth or uteroplacental insufficiency.
 Dysmaturity - characteristics of
chronic malnutrition
- 20 % posttermpregnancies
- uteroplacental
- cord compression
- Meconium passage
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

14. Cont...
Dysmature neonates
 Long thin body, long nails, and are small
for gestational age
 Skin is dry), meconium-stained,
parchment-like, and peeling; prominent
creases; lanugo hair is sparse or absent,
while scalp hair is increas
 ↑ hypoglycemia, polycythemia, perinatal
asphyxia, meconium aspiration, and
persistent pulmonary hypertension. They
are also at risk for neurodevelopmental
complications
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

15. Cont...
• LONG-TERM NEONATAL OUTCOMES
 Does not appear to be any difference in long-term neonatal
outcome compared with term births (small and old studies, )
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

16. MANAGEMENT
• Accurate assessment of gestational age is paramount in the management of late-
and postterm pregnancies.
• Antenatal Surveillance
Studies have not shown one modality of antepartum
surveillance to be superior to another
At 41 weeks or beyond with assessment of amniotic fluid
volume( ACOG)
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

17. Expectant Management Versus Induction of Labor
• Induction of Labor
 Induction , considered for pregnancies that are between 41 0/7 and 41
6/7 weeks.(ACOG)
 Induction of labor after 42 0/7 weeks and by 42 6/7 weeks(ACOG)
Standard cervical ripening
Membrane stripping(resonable ≥ 39 weeks)
- patients should be selected carefully and counseled appropriately.
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

18. Cont...
• Expectant management with fetal surveillance
 Twice-weekly fetal surveillance beginning at 41+0 weeks
 Intervention if spontaneous labor does not begin by a predefined
gestational age or fetal test results are not reassuring of fetal wellbeing
 Timing of delivery; 42+6 weeks of gestation in all
pregnancies(ACOG)
≥ 43 weeks= no strong evidence on which to base a recommendation
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

19. RECURRENCE RISK
• After one postterm pregnancy, the risk of a second postterm birth is increased two-
to fourfold and even higher after two prior postterm pregnancies
• PREVENTION
 Early routine ultrasound examination( decrease intervrntion by
50%)
 Membrane sweeping at term
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

20. “Simplicity is the ultimate sophistication”
- Leonardo da Vinci
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)

21. THANK YOU
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Dr. AKEBOM
(MD, Asssistant professor of Gynecology and Obestetrics,
Mekelle UniversityCollege of Health Sciences)