Giving Birth is a Gas — Or Not

Nitrous oxide for labor pain has little evidence to show effectiveness

(RxWiki News) It's no secret that giving birth is painful. While care providers offer a range of methods to deal with that pain, little is known about one in particular: nitrous oxide.

A recent report reviewed the evidence available on inhaling nitrous oxide to deal with labor pain.

It appears to be less effective than using an epidural, one of the most common forms of childbirth pain relief.

"Discuss your labor plan with your OB/GYN."

The report was commissioned by the U.S. government's Agency for Healthcare Research and Quality.

Carolyn M. Clancy, MD, is director of the Agency for Healthcare Research and Quality, but this report involved several key groups of people, including a panel of experts and additional peer reviewers.

The Vanderbilt Evidence-based Practice Center conducted the actual review of the evidence related to using nitrous oxide for labor pain relief.

The review included English-language articles from the databases MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature.

The group identified five key questions to find out from the research literature, and they excluded studies that did not address one of these questions, were not original research, or had fewer than 20 participants.

The five key questions included the effectiveness of nitrous oxide for labor pain management, the effect of nitrous oxide on women's satisfaction, the effect of nitrous oxide on the route of birth, the adverse effects of nitrous oxide for labor pain management and the effect of the provider and health system factors on its use.

They located 58 total studies that involved 59 groups of women, but only two of these studies were evaluated as being good quality. While 11 were considered "fair" quality, the other 46 were classified as poor quality.

The overall main finding of the report is that inhaling nitrous oxide is not as effective for pain relief as using an epidural. However, the poor quality of the studies made it difficult to conclude that the research found was sufficient.

The studies used a wide variety of different tools, assessments and outcomes to measure women's satisfaction with the birth experience and with the management of labor pain.

This variety made it difficult to compare the outcomes across the studies or to analyze them with a similar set of criteria.

Camran Nezhat, MD, an adjunct clinical professor of OB/GYN at Stanford University Medical Center, said the lack of evidence gives him pause, but more research is necessary.

"Given the limited scope of current research on nitrous oxide for labor pain relief, I would hesitate to recommend nitrous oxide as an alternative method of pain control during labor," Dr. Nezhat said. 

"However, it is a method that warrants more research, especially for women seeking a less invasive, self-administered and a more ambulatory option compared to an epidural," he added.

The most common side effects identified from using nitrous oxide were nausea, vomiting, dizziness and drowsiness.

The outcomes of the babies appeared similar in women who used nitrous oxide compared to women who used other types of pain management or no medical forms at all.

The babies' Apgar scores — a quick test to determine a baby's health at birth — were approximately the same among women using any or no type of pain management in these studies.

However, the report noted that the studies did not offer a lot of information related to the possible harms that could come to hospital staff from the use of nitrous oxide.

The report's ultimate conclusion is that more research is necessary to determine the safety and effectiveness of using nitrous oxide for the pain of labor.

Review Date: 
August 28, 2012