This Practice Advisory was developed by the American College of Obstetricians and Gynecologists' Committee on Clinical Practice Guidelines—Obstetrics in collaboration with Kathleen Brookfield, MD, PhD, MPH; Manisha Gandhi, MD; Anjali J. Kaimal, MD, MAS; and Megan McReynolds.
The use of nitrous oxide (N2O) in labor is addressed in Practice Bulletin No. 209, “Obstetric Analgesia and Anesthesia” 1 . In the Practice Bulletin, it is described that nitrous oxide can be used safely with other forms of analgesia. However, a statement from the American Society of Anesthesiologists noted that in the setting of nitrous oxide analgesia, the addition of systemic opioids or sedatives/hypnotics may lead to deeper levels of sedation and increase the risk of respiratory depression and associated maternal hypoxemic episodes 2 . As a result, if a combination of opioids or sedatives/hypnotics with nitrous oxide is used for labor analgesia, there may be increased risk of adverse events.
Based on this concern for potential maternal adverse consequences, co-administration of systemic opioids or sedatives/hypnotics and inhaled nitrous oxide for labor analgesia is not recommended.