The November/December issue of the Journal of Midwifery & Women’s Health has an article on nitrous oxide by Judith Rooks, a nurse-midwife and epidemiologist who has long advocated for making nitrous oxide available as a pain relief option for U.S. women in labor.
Nitrous oxide (N2O) is a gas that a laboring woman can breathe in through a mask. It works very quickly, taking effect in about a minute, and wears off quickly. Because it is administered by the laboring woman herself, it allows her to obtain a short burst of relief only when needed, as an alternative to an epidural. It is the most commonly used form of analgesia in the United Kingdom.
However nitrous oxide is not widely available in the U.S., despite the endorsement of various childbirth advocacy organizations, including the American College of Nurse Midwives.
In her article, Rooks reviews the research and literature on the safety and risks of nitrous use. She discusses questions around high and low doses of the gas, labor progress, maternal and fetal/newborn effects, and occupational hazards. She notes that:
Because N2O/O2 labor analgesia does not have adverse effects that could threaten the safety of the mother or fetus, laboring women who use it do not need routine intravenous access, continuous electronic fetal monitoring, or other procedures that are intrusive and restrict the mother’s freedom of movement during labor. Nitrous oxide labor analgesia is safe for the mother, fetus, and neonate and can be made safe for caregivers.
The review points out several health concerns, including that women who have had recent ear surgery (because of potential vomiting and inner ear pressure issues) and women who at increased risk of vitamin B12 deficiency may need special review before using nitrous, and that workplaces should take care to make sure the appropriate safety measures are taken to limit birth workers’ exposure. She also points to the need for additional research on issues like brain effects and occupational exposure in birth settings.
Although it’s only available to members, the American College of Nurse-Midwives also covered nitrous oxide in their recent Quickening newsletter. In it, they speak to Michelle Collins, CNM at Vanderbilt, who was instrumental in pushing for nitrous to be an option there. Collins explains several reasons women might choose nitrous: to take the edge off contractions, reduce anxiety, relieve discomfort while waiting on an epidural or during other procedures, or simply to delay epidural and keep more time available when the woman can be mobile.
Collins shares that in one month this summer, “35 women used the nitrous during labor at Vanderbilt, and of those, 22 used it as their sole analgesia. The remaining 13 used it and later had an epidural.”
For more on this topic, see this previous post with further discussion from Judith Rooks.