Nitrous oxide for relief of labor pain: a systematic review

Am J Obstet Gynecol. 2002 May;186(5 Suppl Nature):S110-26. doi: 10.1067/mob.2002.121259.


A systematic review was conducted to determine the efficacy and safety of nitrous oxide for labor analgesia. Eleven randomized controlled trials with adequate control groups and outcome assessment by parturients during or shortly after the intervention were used to determine efficacy. To determine adverse outcome, descriptions found in 8 controlled trials and in 8 observational studies were included. A nonsystematic review of studies on occupational exposure was also conducted. Nitrous oxide is not a potent labor analgesic, but it is safe for parturient women, their newborns, and health care workers in attendance during its administration. It appears to provide adequately effective analgesia for many women.

Publication types

  • Review
  • Systematic Review

MeSH terms

  • Administration, Inhalation
  • Analgesia, Obstetrical / methods*
  • Equipment Contamination
  • Female
  • Humans
  • Nitrous Oxide / administration & dosage
  • Nitrous Oxide / adverse effects
  • Nitrous Oxide / therapeutic use*
  • Occupational Exposure
  • Pregnancy
  • Randomized Controlled Trials as Topic


  • Nitrous Oxide