Over nearly four decades since Prozac was approved for the treatment of depression, waves of concern about the effects of antidepressants during pregnancy have resulted in a practical consensus: Though use of the drugs may be associated with a slight rise in the odds of birth defects, the risk of leaving a mother’s depression untreated is often greater.

But a high-level shift is taking place within the Department of Health and Human Services under Secretary Robert F. Kennedy Jr., who has made reducing the prescription of psychotropic drugs a policy priority.

Among the select group of experts convened by the Food and Drug Administration on Monday to discuss the safety of antidepressants during pregnancy, around half said that women should receive a more clear and forceful warning about potential risks to the fetus.

Andrew Nixon, an H.H.S. spokesman, said the agency would not comment on whether there were plans to require a so-called black box warning about the use of selective serotonin reuptake inhibitors, or S.S.R.I.s, in pregnancy.

In his introductory remarks, F.D.A. commissioner Dr. Marty Makary said that “some women are not aware” of the risks of taking antidepressants in pregnancy, suggesting openness to the idea. Around 5 percent of pregnant American women take antidepressants, he said.

“Serotonin might play a crucial role in the development of organs of a baby in utero,” Dr. Makary said.