Nitrous Oxide: A Painkiller for Childbirth

Nitrous Oxide: A Painkiller for Childbirth

Last update: 18 May, 2018

Have you seen the infamous “laughing gas” in movies or cartoons? It’s nitrous oxide, and for some time now it has been used as a painkiller for childbirth.

The striking thing is that the results seem to be positive. We’ll review more about this curious technique below.

Countries such as Canada, England, Finland, Sweden and Australia usually use this gas to anesthetize women during labor.

This component has a slightly sweet aroma and low toxicity. In addition, for these occasions, it’s mixed with 50% oxygen; this mixture is called entonox.

What is the effect of nitrous oxide?

When used as an analgesic, nitrous oxide neutralizes the cerebral transmission of pain.

Its first uses in the medical field were related to dental extractions. Of course, that pain has little to do with the pain of childbirth.

In principle, women experience some dizziness and relaxation. While the pain is still felt, the gas provides a sense of relief and pain control.

In general, it’s used as the only analgesic agent. Compared with epidural anesthesia, its effectiveness is somewhat lower in terms of pain reduction.

Advantages of nitrous oxide as a painkiller for childbirth

Although in some countries, such as the United States, there are questions about its use or even bans in place, nitrous oxide has the following virtues:

  • It has fast action. Because it doesn’t dissolve in blood and other tissues, it provides rapid anesthesia. Also, its effect disappears shortly after suspending the supply.
  • It is effectively eliminated. This is done mostly through the lungs, although minimal diffusion has also been detected through the skin. The approximate elimination time is two minutes.
Nitrous Oxide: A Painkiller for Childbirth
  • It doesn’t affect the fetus or the mother. It has also been proven that it doesn’t have negative consequences for lactation, nor does it repress uterine contractions.
  • It’s easy to supply. Nurses proceed to place a mask on the mother and, in a matter of seconds, it enters the pulmonary system. In addition, it’s the woman herself who administers the doses.
  • Sensation of natural childbirth. Those who have used it emphasize that nitrous oxide allows for a more natural birth than an epidural. Although the pain is felt a little more, there is no loss of feeling or control below the waist.
  • It’s cheaper than an epidural.

Childbirth is the only blind date in which you’re sure you’ll meet the love of your life.


How is it used?

The curious thing about this method is that it’s the mother herself who doses the inhalation. How does it work?

Once the mask is placed, and according to the phase of delivery, the woman performs more or less deep inhalations while also following the instructions of the nurse or midwife.

Before each contraction, she inhales deeply and slowly. As it takes about 30 seconds to take effect, it usually coincides with the time of greatest pain. Once its effect is gone, the contraction will be over.

This is the basis of its use: to match its maximum painkilling effect with the maximum pain of contraction. Within a couple of attempts, the mothers usually achieve it.

Nitrous Oxide: A Painkiller for Childbirth

Disadvantages of nitrous oxide

The first disadvantage has to do with the pain intensity. As it’s an analgesic and not an anesthetic, it reduces pain but doesn’t suppress it.

Therefore, if it becomes unbearable, the woman should resort to other more powerful methods.

On the other hand, it usually generates nausea. Sometimes this can be very annoying. It occurs between 25 and 30 percent of the time it is used for childbirth.

Finally, although to a much lesser extent, other side effects may also appear:

  • Dry mouth
  • Drowsiness
  • Ringing in the ears
  • Alterations in memory
  • Tingling sensation
  • Feeling of euphoria

Logically, there are also cases in which it’s contraindicated. This is when the mother suffers from lung problems or cranial hypertension. However, this doesn’t happen very frequently.

In conclusion, it can be said that it’s a safe method for women who prefer its use. At the end of the day, it’s a choice for each individual to make: not everyone suffers pain in the same way.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Chen SR., Jin XG., Pan HL., Endogenous nitric oxide inhibits spinal NMDA receptor activity and pain hypersensitivity induced by nerve injury. Neuropharmacology, 2017. 125: 156-165.
  • Shah K., Murphy C., Nitrous oxide toxicity: case files of the carolinas medical center medical toxicology fellowship. J Med Toxicol, 2019. 15 (4): 299-303.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.