The joint opinion from the American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics (AAP) is based on a review of available literature, the groups said.
"Many labor and delivery units are equipped with tubs to be used by laboring women, and immersion in water for relaxation and pain relief is appealing to some," Dr. Jeffrey Ecker, chairman of the ACOG committee that developed the opinion, said in a college news release.
"But it is important to recognize that laboring in water is not the same as delivering underwater," Ecker said. "Laboring in water may offer some potential benefits, but delivering underwater does not seem to have clear advantages, and the risk of rare but serious consequences to a delivering baby's health is something women and providers should all be aware of."
One ob-gyn agreed. "The birthing process imposes the first life stress test for the unborn and perhaps it is the riskiest trip of our lives," said Dr. Anthony Vintzileos, chairman of obstetrics and gynecology at Winthrop-University Hospital in Mineola, N.Y. "I see no reason to make it more risky by laboring or giving birth in the water."
According to the ACOG/AAP statement, potential problems associated with underwater delivery include an increased risk of infection in the mother and baby, difficulty controlling the baby's body temperature, greater risk of umbilical cord damage, breathing problems caused by the baby inhaling water and possible seizures or asphyxiation of the baby after birth.
Hospitals or birth centers that offer water immersion in the first stage of labor should take a number of steps to protect the health and safety of the baby, according to the statement.
These measures include strict guidelines for selecting eligible women, proper cleaning and maintenance of tubs and immersion pools, following infection-control procedures, regular monitoring of women while immersed and removing women from tubs if there are any concerns about them or their babies.
Underwater delivery should be performed only in properly designed clinical trials and with the parents' informed consent, according to the opinion, which was released online March 20 and appears in the April print issue of the journal Obstetrics & Gynecology.
Two other ob-gyns agreed that although underwater birth may help the mother, it might pose a danger to her baby.
"Importantly, the safety and benefit of immersion in water during the second stage, when a woman is pushing, has not been clearly demonstrated," said Dr. Joanne Stone, director of maternal fetal medicine at the Mount Sinai Hospital in New York City. "In fact, there are some case reports of serious adverse outcomes for the newborn."
"Certainly, there needs to be some clear protocols about who are candidates for this type of delivery, as well as strict guidelines for maintenance of these pools in terms of infections, cleanliness and patient selection," Stone said.
Dr. Victor Klein, director of patient safety and risk reduction in the obstetrics and gynecology department at North Shore-LIJ Health System in Great Neck, N.Y., said that "while laboring in a tub until the woman is fully dilated and ready to being pushing may have some benefits, the actual delivery underwater has no benefit to the baby -- with potential serious risks."
The U.S. Office on Women's Health has more about labor and delivery.