10 things to know about Post-Term Pregnancy

1. Normal pregnancy lasts between 37 weeks to 42 weeks. The estimated due date is 40 weeks or 280 days from the first day of your last menstrual period.
2. Post-term (or prolonged) pregnancy last longer than 42 weeks and occurs in 10% of pregnancies. However, most obstetrical providers advise deliveries by 41 weeks.
3. Accurate dating is important in the diagnosis of post-term pregnancy. Ultrasound before 24 weeks can accurately date the pregnancy.
4. The cause of post-term pregnancy is unknown. Post-term pregnancy happens more often in first pregnancies and in women who have had previous post-term pregnancy.
5. The risks to the mother in post-term pregnancy include:
   • Difficult and prolonged labor with a larger baby
   • Increased risk of cesarean section
6. The risks to the baby in post-term pregnancy include:
   • Stillbirth or infant death near time of birth (4-7/1000 deliveries) increases after 40 weeks and doubles after 42 weeks gestation. For women older than 35, the risk of stillbirth increases after 37 weeks of pregnancy.
   • Birth trauma with difficulty delivering shoulders (shoulder dystocia) which may result in nerve injuries
   • "Post maturity syndrome" with intrauterine growth restriction or insufficient growth of the baby, decreased amniotic fluid with increased risk of cord compression, and long term neurological defects
   • Meconium aspiration (baby inhaling bowel content) resulting in breathing problems
7. Fetal monitoring recommended by your doctor may include:
   • Kick Count
   • Non stress test
   • Biophysical profile
   • Contraction stress test
8. If labor does not begin by 41 or 42 weeks, labor may be initiated by:
   • Induction of labor or
   • Cesarean section
9. Delivery decision depends on:
   • Fetal well-being
   • Cervix favorable or soft enough to induction
   • Gestational age
   • Maternal preference
10. The American College of Obstetricians and Gynecologists (ACOG) recommends that delivery be initiated if there are signs of fetal compromise or oligohydramnios (low amniotic fluid).