Oct. 10 (UPI) -- Women who pushed immediately when fully dilated during a vaginal delivery had a shorter average labor than those asked to delay, as well as fewer medical problems, according to a study.
Researchers studied the effects of commonly delaying pushing during the second stage of labor when the cervix is fully dilated at 10 centimeters. In the findings, published Tuesday in the Journal of the American Medical Association, they found delaying pushing may have no effect on whether pregnant women deliver spontaneously -- without a cesarean section or other intervention. In addition, women who pushed earlier had fewer bacterial infections and excessive bleeding after delivery.
All the women in the study received epidural anesthesia, which is an anesthetic injected into the spinal column to reduce labor pain.
"The findings provide strong evidence that for the vast majority of first-time mothers receiving epidural anesthesia, delaying pushing offers no benefit over immediate pushing at the second stage of labor," Dr. Menachem Miodovnik, a medical officer in the Pregnancy and Perinatology Branch of the National Institute of Health's Eunice Kennedy Shriver National Institute of Child Health and Human Development, said in a press release.
In previous research, evidence supporting delayed pushing was inconclusive.
In a large study more than 20 years ago, delayed pushing reduced the rate of deliveries in which forceps -- surgical tongs -- are inserted high into the birth canal to help turn and pull the baby forward. But high forceps are no longer commonly used in the United States because of risks to mother and infant.
In a later meta-analysis of the older study, and several smaller studies, researchers found no difference in spontaneous delivery between immediate and delayed pushing at the second stage of labor.
For the new study, researchers randomly assigned 2,414 women at 37 weeks of pregnancy or later to immediate or delayed pushing between 2014 and December 2017 at six U.S. medical centers. Only first-time mothers with a single pregnancy were included in the study.
With the cervix dilated fully, women were told to begin pushing immediately or to delay pushing for 60 minutes -- unless their clinician instructed them otherwise or they had an irresistible urge to push. Women in the immediate pushing group could begin pushing as soon as the second stage began.
The rate of spontaneous delivery was 85.9 percent for the immediate group compared with 86.5 percent in the delayed group.
The immediate group had a shorter average duration of labor by 32 minutes. And the immediate group pushed for nine minutes more than the delayed group -- 83.7 minutes vs. 74.5 minutes.
The immediate pushing group had a 6.7 percent rate of chorioamnionitis -- infection of the placenta and membranes surrounding the fetus -- compared with 9.1 percent for the other group.
Also, 2.3 percent in the intermediate group had postpartum hemorrhages, known as excessive bleeding following delivery, compared with 4.0 percent for the delayed group.
The study was stopped after enrolling 75 percent of the planned participants because the researchers believe results were unlikely to differ substantially at full study recruitment, in addition to concerns about a higher risk of postpartum hemorrhage and chorioamnionitis among those delaying pushing.