When women in labor are given more time to deliver their baby than current guidelines recommend, their incidence of cesarean delivery drops by 55 percent, say researchers at Thomas Jefferson University.
Their study, in the March issue of the American Journal of Obstetrics and Gynecology, is the first to formally test what happens when women in the second stage of labor (fully dilated) are given four hours, instead of three, if they did have an epidural.
Not only was the incidence of cesarean delivery reduced by more than 50 percent, there were no associated negative health consequences to the mother or child, says the study's lead author, Alexis C. Gimovsky, M.D., a Maternal Fetal Medicine Fellow at The Sidney Kimmel Medical College of Thomas Jefferson University.
The findings suggest that the two-hour rule, which dates back to the 1800s, needs to updated, she says. "This was a small study, so a formal change in guidelines should be based on a larger sample of women. But this study shows what we have observed in practice—there is benefit to allowing women to labor longer."
The current guidelines do allow some flexibility so some obstetricians already provide extra time to labor, on a case-by-case basis, Dr. Gimovsky says. "But, for the sake of reducing the number of cesareans that are performed in this country, we should further investigate expanding the time frame."
About 30 percent of deliveries in the U.S. end with a caesarean, which can put a woman at risk for a number of complications in following pregnancies, can impact fetal health, and which are very costly, she says.
About 10-15 percent of the cesareans for first time mothers result from the two-hour rule, she adds. Allowing three hours if a woman has had an epidural—medicine that relieves labor pain by blocking nerve signals—was added on to labor guidelines by the American College of Obstetricians and Gynecologists in the 1980s.
In this study, Dr. Gimovsky and the study's senior author, Vincenzo Berghella, M.D., Director of Maternal Fetal Medicine at Thomas Jefferson University Hospital, enrolled 78 first time mothers who were between 36-41 weeks of gestation. They were randomized to an "extended labor" group that allowed for at least one additional hour of labor, or to a "usual labor" group that followed current delivery guidelines. At time of delivery, all of the study participants chose to have an epidural. Almost half of the women had an induced labor.
They found that incidence of cesarean delivery was about 19.5 percent (8 out of 41 women) in the extended labor group and about 43 percent (16 of 37 women) in the usual labor group. There were no statistically significant differences in maternal or neonatal morbidity outcomes between the groups.
Dr. Gimovsky noted that many expecting mothers were eager to join the study, suggesting "a majority of women are highly motivated to have a vaginal delivery," she says. "Changing the guidelines may help many women reach that goal."
Explore further: Effectively predicting cesarean delivery in nulliparous women
Alexis C. Gimovsky et al. Randomized controlled trial of prolonged second stage: extending the time limit vs usual guidelines, American Journal of Obstetrics and Gynecology (2016). DOI: 10.1016/j.ajog.2015.12.042