Why a longer labor could cut cesarean delivery rates
A small randomized controlled trial published in The American Journal of Obstetrics & Gynecology suggests that allowing women more time in the prolonged second stage of labor could drastically reduce the cesarean rate.
Researchers at the Sidney Kimmel College of Medicine at Thomas Jefferson University in Philadelphia, Pennsylvania assessed data on nulliparous women with singleton pregnancies at 36 0/7 to 41 6/7 weeks’ gestation. All of them reached the American College of Obstetricians and Gynecologists definition of prolonged second stage of labor: either 3 hours with epidural anesthesia or 2 hours without epidural anesthesia.
Randomization was to either extension of labor by 1 additional hour or to the usual labor, defined as expedited delivery either via cesarean delivery or operative vaginal delivery. Exclusion criteria included intrauterine fetal death, age < 18 years, planned cesarean delivery, and suspected major fetal anomaly.
Overall 78 women were assigned randomly and all of the women had epidural anesthesia. The demographics of the women in the two study arms were not significantly different. In the extended labor group, the rate of cesarean delivery was 19.5% or 8 out of 41 births. In the usual labor group, the rate of cesarean delivery was 43.2% or 16 out of 17 births (relative risk, 0.45; 95% confidence interval, 0.22–0.93). The number needed-to-treat to prevent 1 cesarean delivery was 4.2. No statistically significant differences were seen in maternal or neonatal morbidity outcomes between the 2 groups.
The researchers concluded that extending labor in nulliparous women with a singleton pregnancy, under epidural anesthesia, and in a prolonged second stage seemed to decrease the rate of cesarean delivery by a little more than 50%. They pointed out that the study was underpowered in its ability to detect small differences, which could have some clinical importance.