Maternal-fetal outcomes in prolonged pregnancy

The normal period of gestation, from conception to delivery, is 40 weeks. Pregnancies continuing beyond 42 weeks (294 days from the last menstrual period) can result in poor outcomes for the infant and mother. To reduce the number of deaths from a prolonged pregnancy, most practitioners will use drugs which induce labor. The effect of a prolonged pregnancy on the mother and fetus was evaluated in 379 pregnancies continuing beyond 42 weeks gestation. The fetal heart rate, the characteristics of the labor and delivery, and the infant outcome were monitored. Labor was drug-induced in 48 percent and augmented in 28 percent of the women. Cesarean delivery was performed in 13 percent of the patients and delivery was assisted by forceps in 15 percent of the deliveries. The birth canal was unable to accommodate the passage of the infant in 60 percent of the cesarean sections and 13 percent of the infants were too large to deliver vaginally. Particularly fast fetal heart rates were detected in 39 percent of the infants. Inducing labor did not increase the need for cesarean section. It was concluded that preventive measures such as labor induction are a justified intervention in the treatment of prolonged pregnancies.