Longer labor is linked to adverse outcomes, so doctors usually reduce or discontinue epidurals to avoid prolonging the main stage of labor. But a study in Obstetrics & Gynecology suggests there aren't benefits in doing so.
"Obstetric providers frequently turn the epidural infusion down, or even off, when a patient has difficulty in the second stage," Hess said. "This study shows that that does not improve the chance of a vaginal delivery, but exposes the woman to unnecessary pain."
Research led by his team found that an epidural doesn't affect the length of the second stage of labor. It also has no effect on rates of vaginal delivery or episiotomy, nor does it impact the position of the fetus at birth. The medication also did not affect weight, Apgar scores or other well-being measures.
"Not even the pain scores were statistically different between groups. However, pain scores in women receiving the saline placebo increased over time, as would be expected," he said.
The double-blind randomized study compared catheter-infused epidural medication compared to a placebo in 400 women. During the study, women all got pain medication via a patient-controlled pump during the first stage of labor. During the second stage, they were randomized to receive the medication or a placebo.
Labor lasted about 52 minutes for those given medication, compared to 51 minutes for those who got the saline.
In 38 patients, the infusions were stopped due to poor labor progression; of them, 17 were on saline and 21 had epidural medication.
Previous studies were retrospective, observational, or have focused on other labor outcomes and have not controlled the second stage, Hess noted.
"What this suggests is that women should not fear that if they choose to receive epidural medication it will affect their labor," Hess said.