(AP) -- Labor pain is nothing to laugh at. Yet.

The use of nitrous oxide, or laughing gas, during childbirth fell out of favor in the United States decades ago, and just two hospitals - one in San Francisco and one in Seattle - still offer it.

But there are signs of a comeback for managing the pain of labor and delivery. Respected hospitals, including New Hampshire's Dartmouth-Hitchcock Medical Center, plan to start offering it. Laughing gas is being reviewed by the federal government and after a long hiatus, the equipment needed to administer it is expected to hit the market soon.

Advocates emphasize it's no silver bullet, but they say it should be among the options offered to women because it's easy for women to self-administer, takes effect quickly, and can be used in the later stages of labor.

Explore further Study finds women used 30 percent less analgesia during labor when self-administered

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