Epidural analgesics have no effect on the duration of the second stage of labor, study reveals

A study, published in the journal Obstetrics & Gynecology, indicated that epidural analgesia had no impact on the duration of the second stage of labor, fetal position during birth, prevalence of episiotomy, normal vaginal delivery rate, or any other fetal well-being measures investigated by researchers.

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In this study, the impacts of low-concentration, catheter-infused epidural anesthetic are compared to a saline placebo infused by catheter.

Epidural analgesia, a combination of narcotics and anesthetics delivered by catheter positioned close to the spine nerve, is the most efficient technique for labor pain relief. In extensive utilization since the 1970s, epidural analgesia has been assumed to slow down the second stage of labor- defined as arising when the cervix is entirely dilated and culminating after the delivery of baby.

A longer interval of the second stage of labor has been considered linked with undesirable consequences, obstetricians regularly discontinue or decrease epidural pain management in an attempt to hasten this essential stage of labor. According to research by Beth Israel Deaconess Medical Center (BIDMC), that procedure could be misguided and out-of-date.

Philip E. Hess, MD, Director of Obstetric Anesthesia at BIDMC and senior author of the study stated: "We found that exchanging the epidural anesthetic with a saline placebo made no difference in the duration of the second stage of labor."

He further added that there is no statistical difference in the pain scores of the groups. Nevertheless, pain scores in women taking the saline placebo intensified over time, as would be expected.

The study included 400 healthy, first-time mothers. During their first stage of labor, they were offered with an epidural analgesic pump that can be controlled by them. Active pain medication was given to all the mothers during this initial stage of labor.

During their second stage of labor, the mothers were randomized to take either the saline placebo or low doses of the active analgesics. In this stage of labor, neither the obstetricians, investigators, midwives, or the mothers knew whether they are administered with catheter-infused saline placebo or the active pain medication in this double-blind trial.

Women with extreme pain were administered with unblinded active analgesics at their obstetrician’s discretion and the epidural infusions can also be terminated by doctors at any time on the basis of clinical indicators.

The primary consequence, the time duration of the second stage of labor, was alike in both groups: around 52 minutes for mothers administered with active analgesics versus around 51 minutes for mothers administered with the saline placebo -- just a difference of 3.3%. The average periods were also same: 45 minutes for mothers on active analgesics versus 46 minutes for those on saline placebo.

Note that the obstetricians were asked to stop epidural infusions in 38 patients due to the poor labor progression. Of these, 17 of the mothers were from the saline group and 21 of those from the active medication group.

Hess also stated that twice as many mothers administered with the saline placebo reported poorer satisfaction with their pain relief compared to those administered with active anesthetics.