By Birth & Baby University · Last updated: October 2026 · 3 min read
Nitrous oxide is long established in many countries and increasingly offered in North American hospitals and birth centers. Clients may ask whether it is “safe,” how strong it is and whether it affects the baby. This article summarizes what the reviews show and where the evidence is thin.
Key takeaways
- Cochrane found nitrous oxide relieved pain more than placebo or no treatment but caused more nausea, vomiting, dizziness and drowsiness.
- A systematic review judged it less effective than epidural, though most studies were of poor quality.
- Reviews found no significant Apgar score differences in newborns, and a safety review concluded it is safe for mother, fetus and neonate when used as a self-administered 50 percent blend with oxygen.
- Evidence on occupational exposure for staff and others in the room was limited.
What the research says
Effectiveness and side effects
The Cochrane review of inhaled analgesia included 26 studies with 2,959 women. Placebo or no treatment offered less pain relief than nitrous oxide (average RR 0.06, 95% CI 0.01 to 0.34, two studies, 310 women), but nitrous oxide caused more nausea, vomiting, dizziness and drowsiness, with very wide confidence intervals driven by small numbers. Flurane derivatives provided better pain relief than nitrous oxide in the first stage, in a few small cross-over trials of questionable design, and caused less nausea. There were no significant differences between strengths or delivery systems, or against TENS. The review noted substantial heterogeneity for some analyses.
A 2014 systematic review of 58 publications found that nitrous oxide gave less effective pain relief than epidural, but that study quality was predominantly poor (two good, 11 fair, 46 poor). Satisfaction outcomes were too varied to synthesize. Most maternal adverse effects were unpleasant ones that affect tolerability: nausea, vomiting, dizziness and drowsiness. Apgar scores did not differ from newborns of mothers who had other pain management or none. The review said evidence about occupational harms and exposure was limited.
Safety
A 2011 review in the Journal of Midwifery and Women’s Health examined effects on labor, the mother, fetus, neonate, breastfeeding and bonding, and addressed concerns about brain cell death in immature animals, cardiovascular risk, later amphetamine addiction and occupational exposure. It concluded that nitrous oxide is safe for mothers, neonates and caregivers when delivered as a 50 percent blend with oxygen, self-administered, with good occupational hygiene, and that it does not interfere with endogenous oxytocin or the progress of labor. This review mainly synthesized other reviews, so it is a secondary source, and a reader should weigh its conclusions alongside the poor quality of the primary studies noted above.
Where it fits
The Cochrane overview of labor pain management reviews placed inhaled analgesia, with epidural and combined spinal epidural, in its “what works” category for managing pain, but flagged that women using it were more likely to experience vomiting, nausea and dizziness.
What this means for doulas
- Describe it as partial relief. The evidence does not support calling it a substitute for an epidural, and some people find it takes the edge off while others find little effect.
- Prepare clients for side effects. Nausea, dizziness and drowsiness are common, and a client who knows this may adjust how they use it.
- Know the supervision rules. It is self-administered with a mask or mouthpiece in a facility that has the equipment and trained staff. Doulas do not handle the equipment.
- Be accurate about safety. The reviews found no evidence of harm to babies at standard doses, but the primary evidence is of poor quality.
Putting the evidence into practice
- Ask in prenatal visits whether the planned birth place offers nitrous oxide and what the criteria are.
- Help clients practice the timing idea taught in many settings: begin inhaling as a contraction starts, not at its peak. Confirm this with the facility’s own instruction.
- Be prepared to help a person who feels dizzy by keeping them seated or supported, and tell the nurse.
- Respect the choice to stop using it or move to another option.
The bottom line
Nitrous oxide is a reasonable, self-controlled option that offers partial pain relief and has not been shown to harm babies, with side effects and weak primary evidence worth naming. Doulas support informed choice and leave equipment and clinical decisions to staff.
This article is for professional education. It is not medical, legal or tax advice. Check the standards of your certifying organization and the rules where you work.
Sources and further reading
- Klomp T, et al. Inhaled analgesia for pain management in labour. Cochrane Database of Systematic Reviews 2012. Read the source
- Likis FE, et al. Nitrous oxide for the management of labor pain: a systematic review. Anesthesia and Analgesia 2014. Read the source
- Rooks JP. Safety and risks of nitrous oxide labor analgesia: a review. Journal of Midwifery and Women’s Health 2011. Read the source
- Jones L, et al. Pain management for women in labour: an overview of systematic reviews. Cochrane Database of Systematic Reviews 2012. Read the source
Understanding all the pain relief options your clients may meet helps you support informed choices. See the training options on the For Doulas page.
More for professionals: the Professionals Blog.
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