Nitrous Oxide During Labor

Image of a pregnant woman using nitrous oxide during her labor

Using Nitrous Oxide During Labor: Benefits and Risks

As your due date approaches, you will want to become familiar with the natural and medical intervention options for pain relief. One option for pain relief during labor is nitrous oxide. As with many medical interventions, it does have some risks, but overall it is considered safe to use during labor.

In high concentrations, nitrous oxide is a weak anesthetic. In low doses, however, it is an anxiolytic (a drug used for anxiety relief) and an analgesic (a drug used for pain relief). According to the American College of Nurse-Midwives (ACNM), “Research has supported the reasonable efficacy, safety, and unique and beneficial qualities of N2O as an analgesic for labor and its use as a widely accepted component of quality maternity care” (2011).

In fact, several countries with high standards for health care, such as Canada, Sweden, Australia, Finland, and the United Kingdom, use a blend of 50% oxygen and 50% nitrous oxide to treat pain during labor. Although nitrous oxide was historically used in the United States for pain during labor, it was never used to the same extent as in other countries.

In the United States, the most common pharmacological forms of pain analgesia for labor have been narcotics and local anesthetics through an epidural. Nonetheless, in recent years, there has been a growing awareness of the benefits of using nitrous oxide for pain during labor.

Benefits of Nitrous Oxide During Labor

There are many advantages of using nitrous oxide for labor analgesia:

  • According to the Journal of Midwifery & Women’s Health, “Nitrous oxide labor analgesia is safe for the mother, fetus, and neonate and can be made safe for caregivers. It is simple to administer, does not interfere with the release and function of endogenous oxytocin, and has no adverse effects on the normal physiology and progress of labor” (Rooks, 2011).
  • By not disrupting the release of oxytocin, nitrous oxide does not affect infant alertness during the early bonding period between a mother and her newborn.
  • It does not affect breastfeeding.
  • It does not increase the need for neonatal resuscitation.
  • In the doses given during labor, nitrous oxide is not a strong analgesic. Women who use nitrous oxide during labor may still have an awareness of labor pain. However, many women find it helps them relax and decreases their perception of labor pain.
  • Because it is self-administered, not only can a woman decide how much to use, but she can also decide if she wants to stop using it and try another method of pain relief instead. Nitrous oxide can be easily discontinued, and its effects disappear within five minutes after cessation.

Risks of Nitrous Oxide During Labor

While there are many benefits of using nitrous oxide during labor, there are some risks to be aware of. For example, side effects may include sedation, dizziness, nausea, and vomiting. There is also concern that the repeated use of nitrous oxide by health workers such as nurses and midwives may pose reproductive risks.

However, such occupational exposure to nitrous oxide can be significantly decreased through the use of ventilation and proper equipment, as well as by limiting frequency and length of time of exposure.

In addition, one study has shown a dose-dependent association between intrapartum exposure to nitrous oxide and addiction to amphetamines later in life. However, the mothers in the study used 100% nitrous oxide rather than the 50% concentration required by nitrous oxide safety standards.

Nonetheless, more research is needed on the effects of intrapartum exposure to neuroactive drugs on infants. Fertility problems have also been shown in animal studies using prolonged exposure to very high doses of nitrous oxide. However, because these doses were much higher than what current standards allow, these studies are less applicable in clinical settings.

Nitrous oxide used as anesthesia, not analgesia, does have further risks associated with increased dosage. Recreational nitrous oxide drug users and surgical patients who are given high concentrations of nitrous oxide anesthesia, not analgesia, for more than five hours are also at greater risk of developing certain acute conditions and neurotoxic symptoms related to vitamin B12 deficiency.

These, however, can be treated with vitamin B12 supplements. Nonetheless, women who have a vitamin B12 deficiency should not use nitrous oxide. Nitrous oxide may also cause changes in pressure in the inner ear, so women who have had a recent ear surgery should likewise not use nitrous oxide.

While there are some risks of using nitrous oxide during labor, these are limited through safety standards.

Requirements for the safe use of nitrous oxide analgesia include the following:

  • The nitrous oxide concentration must not exceed 50%.
  • The nitrous oxide must be self-administered by the woman holding a mask to her face.
  • The equipment releasing nitrous oxide must use scavenging equipment and have a demand valve.

Interest in using nitrous oxide analgesia during labor has grown in recent years. Nonetheless, more research is needed on the use of nitrous oxide as a labor analgesic.  While nitrous oxide analgesia may not be effective for every woman, it is considered a fairly safe and low-cost way to treat pain during labor.

Last Update: 08/2015

Compiled from the following sources:

American College of Nurse Midwives. (2011). Nitrous oxide for labor analgesia. Retrieved from Merriam Webster. (n.d.).  Anxiolytic. Retrieved from Oxford Dictionaries. (n.d.). Analgesic. Retrieved from Rooks, J. P. (2011). Safety and risks of nitrous oxide labor analgesia: A review. Journal of Midwifery & Women’s Health, 56 (6). Retrieved from