Repeated or lengthy use of general anesthetic and sedation drugs in infants, toddlers and pregnant women in their third trimester might damage children’s developing brains, the U.S. Food and Drug Administration warned this month.

Upset that the warning about pregnant women was based solely on animal studies, the American College of Obstetricians and Gynecologists, or ACOG, shot back its objection.

“ACOG is unaware of data on pregnant women that support the FDA’s claims,” the group said in a practice advisory to its members. “These warnings may cause patients and providers to inappropriately reject the use of these medically indicated drugs.”

Dr. Chris Zahn, vice president of practice activity for ACOG, said that the nonprofit, which represents physicians who care for women, and the FDA have had a close working relationship and in the past have discussed similar warnings before they were announced. But the warning about pregnant women and anesthesia was different.