Pregnancy & Birth
Nitrous Oxide for Pain Relief in Labor
Nitrous oxide is an odorless, tasteless gas that you breathe in through a mask. Exactly how nitrous oxide works is not well understood, but many women who use it during labor find it beneficial. Although women who use nitrous oxide don’t necessarily report less pain, they report feeling that while they still have some pain they are not as bothered by it. Nitrous oxide can be administered by an anesthesiologist, a midwife, or an obstetrician. It is the most commonly used form of analgesia in the United Kingdom, where midwives use it in hospitals and carry it with them to home births, and three of every five women use it at some time during labor.21
Nitrous oxide has not been used much in the United States. Yet it provides better analgesia than morphine, meperidine (Demerol), or fentanyl.22 In a 2002 national survey, 52 percent of the women who used nitrous oxide found it to be very or somewhat helpful.23 It is safer than the narcotics/opioids and doesn’t have any of the adverse side effects for mothers or babies that can occur after using narcotics/ opioids or epidurals.24 Another advantage is that it takes effect in about a minute and the effect stops quickly once you stop breathing the gas through the mask.
Some women find it difficult to synchronize use of the gas with the timing of their contractions in order to achieve maximally effective pain relief. In the UK, midwives teach women how to do this during prenatal care. Some women find that a mask makes them feel claustrophobic or don’t like the way the gas makes them feel. Some women experience dizziness or nausea.
Nitrous oxide for relief of labor pain is mixed half-and-half with oxygen and delivered through a mask or tube that the laboring woman holds. The gases are delivered either from a hospital pipeline through the walls into the labor rooms or from two separate portable cylinders. Women must begin breathing the mixture through the mask at least 1 minute before the onset of a contraction and continue until the contraction begins to ease.
Self-administration is an essential safety measure. You must hold the mask or tube yourself and not let another person hold it for you. If you breathe too much of the gas, you will become drowsy, your hand will relax, and the mask or tube will fall away from your face, so that you breathe normal room air. Self- administration also allows the woman to control management of her pain.
Nitrous oxide is not widely available for use in labor in the United States. Laboring women in the United States have fewer options for pain relief than women in most other countries in the industrialized world. It is unclear why nitrous oxide is not used often in obstetrics in this country. Ether and chloroform, the other anesthetic gases that were used by women in labor in the early 1900s, were associated with complications and therefore most gas anesthetics went out of favor as other medications became available. Used with current equipment and procedures, nitrous oxide is safe, is effective enough for many women, and has important advantages compared to other, much more commonly used methods of labor analgesia. More women should have access to this method.25
For more information, see Expanded Discussion of Nitrous Oxide for Labor Pain Relief.
NOTES21. M. A. Rosen, “Nitrous Oxide for Relief of Labor Pain: A Systematic Review,” American Journal of Obstetrics and Gynecology 186 (2002): S110–126. [back to text]
22. Ibid. [back to text]
23. Eugene R. Declercq, Carol Sakala, Maureen P. Corry, Sandra Applebaum, and Peter Risher, Listening to Mothers: Report of the First National U.S. Survey of Women’s Childbearing Experiences (New York: Maternity Center Association [now Childbirth Connection], 2002. [back to text]
24. Rosen, “Nitrous Oxide.” [back to text]
25. Adapted with permission from Judith Bishop, “Administration of Nitrous Oxide in Labor: Expanding the Options,” Journal of Midwifery & Women’s Health 52 (2007): 308–09; Judith Rooks, “Use of Nitrous Oxide in Midwifery Practice—Complementary, Synergistic, and Needed in the United States,” Journal of Midwifery & Women’s Health 52 (2007): 186–89. [back to text]
Excerpted from Chapter 11: Coping with Pain in Our Bodies, Ourselves: Pregnancy and Birth © 2008 Boston Women's Health Book Collective.
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