Nitrous Oxide in Labor


There are many comfort measures available to laboring women. The most common medical option is epidural anesthesia which typically eliminates most or all of the pain, but also can severely limit your mobility. Other medical options exist including intramuscular and IV drugs. Another option that is becoming more widely in available in the United States is ‘laughing gas’ also known as nitrous oxide. Nitrous Oxide was previously used in high concentrations for anesthesia or pain relief but can be used in smaller concentrations as an an anxiolytic or antipsychotic. As an antipsychotic rather than decreasing the pain itself, it diminishes the perception of pain. As an anxiolytic it helps with the symptoms of anxiety.

One benefit of nitrous oxide is that it is not known to affect hormone release. This is especially vital when considering Oxytocin as nitrous oxide should not affect breastfeeding or infant alertness during the early bonding period between a mother and newborn. Nitrous oxide is also not known to increase the need for neonatal resuscitation as some of the other medications do. And the best part is that it is self-administered through an oxygen mask, so the laboring woman has the choice of when and how long it should be administered. Many women choose to inhale the nitrous in between contractions. Countries such as Canada, Sweden, Australia, Finland, and the United Kingdom have nitrous oxide available in most of their hospitals.

A few possible side effects of nitrous oxide include sedation, dizziness, nausea, and vomiting. Prolonged exposure can be risky to health care workers however with caution that can be eliminated. One study found a potential link between intrapartum exposure to nitrous oxide and addiction to amphetamines later in life. This study however was performed on rats and used 100% Nitrous compared to the 50% Nitrous and 50% Oxygen used in hospitals today. Another risk is a mother who is deficient in vitamin B12, this would include women with hereditary vitamin B12 deficiency disorder, pernicious anemia, Crohn’s disease, ileal disease, or chronic malnutrition due to alcoholism. In addition, pregnant women who follow a strict vegan diet are also at risk as their B12 concentrations may also be low.

Although Nitrous may sound like a great addition to your birth plan, there are necessary guidelines that need to be followed in order to guarantee safety, these standards include:

  • 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. Scavenging equipment is used to collect and remove waste gases from the patient breathing circuit and the patient ventilation circuit.

Interest in nitrous oxide during labor has increased in recent years, and is now available in a few hospitals and multiple birthing centers in the United States. Nitrous Oxide use in this way is considered safe as stated by the American College of Nurse-Midwives, “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.” That said, more research needs to be done on Nitrous Oxide as a mechanism for combatting pain in labor.