Health I.Q.: Antidepressants and Pregnancy

When it comes to mixing pregnancy and antidepressants, questions and controversy abound.

Taking any medications while pregnant or breastfeeding can induce anxiety in even the most confident of moms-to-be and new mothers. But antidepressants are particularly fraught, as illustrated in an article from The New York Times last fall on their usage by pregnant women, which critics called out almost immediately for being alarmist.

“Unfortunately, many health care providers assume all antidepressants pose significant risks during pregnancy and while breastfeeding,” explains Dr. Carl P. Weiner, coauthor of The Complete Guide to Medications During Pregnancy and Breastfeeding (St. Martin’s Griffin), perinatologist and professor of pharmaceutical sciences at the University of Kansas School of Medicine.

Why the disconnect? Weiner chalks it up to “a lack of comprehensive study of most medications during pregnancy.”

Thankfully, “for many antidepressants,” says Weiner, “we do have information that can help health care providers either proactively change a medication or its dosing schedule to minimize the potential for an adverse effect on a woman or her developing baby.”

Determining the current need for a drug is, however, important. “Even a small, theoretical risk of a medication is not worth taking if a medication is unneeded or ineffective,” Weiner continues. “At the same time, for women who do need and benefit from antidepressant therapy, not taking the medication can pose a greater risk to their unborn children.”

The caution doesn’t stop when a baby is born; breastfeeding can pose a different challenge. Safe usage while nursing hinges on how much of a medication is released into breast milk, if a drug is orally absorbable and a baby’s weight and age.

A chart, produced recently by the Motherisk program at the University of Toronto, can help determine what works and what might not by calculating the relative infant dose: the amount of a drug received by a baby through milk divided by the mother’s weight-adjusted dose. Weiner points out that, typically, if an infant receives less than 10 percent of a mother’s weight-adjusted dose of a drug it is considered safe for breastfeeding. Most antidepressants prescribed today rarely reach that 10 percent mark.