Gynaecological
Post-Term Pregnancy
Overview
Dr. Mona Ahmed
1. Normal Duration of Gestation
Definition and Average Length
Definition: The period between conception and birth. Average length:
- 280 days / 40 weeks from the first day of the Last Menstrual Period (LMP).
- 266 days / 38 weeks from conception (ovulation/fertilization).
Variations: Normal pregnancies may range from 37 to 42 weeks.
2. Classification of Pregnancy by Gestational Age
Categories Based on Gestational Age
- Preterm: < 37 completed weeks.
- Term pregnancy (37–41+6 weeks):
- Early term: 37+0 to 38+6 weeks
- Full term: 39+0 to 40+6 weeks
- Late term: 41+0 to 41+6 weeks
- Post-term (Prolonged) pregnancy: ≥ 42+0 weeks.
Complications of Post-Term Pregnancy
Maternal Complications
Maternal complications:
- Increased operative vaginal delivery and cesarean section.
- Birth canal trauma
- Postpartum hemorrhage.
- Infection risk
Fetal Complications
- Macrosomia
- Oligohydramnios
- Meconium aspiration syndrome.
- Fetal Dysmaturity syndrome
- Stillbirth and increased perinatal mortality.
Evaluation of a Patient with Prolonged Gestation
Careful Dating and Antenatal Fetal Surveillance
Careful dating (LMP, early US). Antenatal fetal surveillance:
- Non-stress test (NST).
- Biophysical profile (BPP).
- Amniotic fluid index (AFI).
Management
1. Confirm Dates
Make sure the due date is correct
If 42 Weeks & Cervix is Ready Induce labor (start delivery process).
2. If Cervix is Not Ready
Do twice-a-week:
- NST (check baby’s heart rate)
- BPP (check baby with ultrasound)
- Amniotic fluid check
If tests are normal → wait.
If tests are abnormal → induce labor.
3. During Labor
- Monitor baby’s heart closely.
- Keep mom lying on left side.
- If baby shows distress → do C-section