Antidepressants pose low birth defect risk

Jeff Donn

Newborns face little risk of birth defects from antidepressants taken by many women early in pregnancy, say the reassuring findings of the two biggest studies of this controversial link.

The research focuses on the class of drugs chosen most often for depression and anxiety, including the brands Prozac, Paxil and Zoloft.

Paxil carries a warning of possible heart defects in newborns, and experts don’t expect the recently published research to change that. However, they find the studies comforting for women struggling with depression.

The possibility of birth defects from antidepressants has put doctors and patients in a tricky quandary. Birth defects obviously hurt newborns, but depressed mothers who can’t give proper care also endanger their babies.

Confusing matters, researchers have wondered if the concern about birth defects should extend beyond Paxil to this entire class of drugs, known as selective serotonin-reuptake inhibitors, or SSRIs. The two latest studies, which appeared in the June 28 edition of The New England Journal of Medicine, relieve some of that worry, according to birth specialists.

“Yeah, there’s a risk, but the risk overall is probably pretty small,” said Dr. Susan Ramin, obstetrics chairman at the University of Texas Medical School in Houston, who was familiar with the findings.

The two studies — one from the federal Centers for Disease Control and Prevention, the other from Boston University — use more cases of birth defects than previous research to consider links between the abnormalities and SSRIs. The Boston University study was funded partly by the National Institutes of Health and Paxil maker GlaxoSmithKline PLC.

Neither study was able to tie SSRIs as a group to either heart defects or most other defects. That reassurance is especially welcome because depressed women fret even more than other mothers about the health of their newborns, said Dr. Stephan Quentzel, a psychiatrist who treats pregnant women at Beth Israel Medical Center in New York City.

Also, a mother’s untreated depression can lead to poor care or turmoil at home, a weaker maternal bond, and other problems for a newborn.

“The fetus and the newborn are almost always worse off if the mom is depressed than if … exposed to the vast majority of antidepressants,” Quentzel said.

However, doctors and mothers have been very wary about medications and birth defects since Europe’s thalidomide scandal in the 1960s, in which fetuses exposed to the drug suffered deformities. Defects from all causes are expected in about 3 percent of births, enough to make many mothers nervous.

The concern about SSRIs grew out of GlaxoSmithKline’s own alert in 2005 about possible heart defects in newborns whose mothers took Paxil early in pregnancy. The U.S. Food and Drug Administration added its own warning. Last year, a separate study linked SSRIs taken late in pregnancy to a lung disorder in newborns.

The latest studies do not consider that disorder, known as persistent pulmonary hypertension. But they suggest that the risk of other defects from an SSRI — even if confirmed — would add only a fraction of 1 percent to the overall danger, researchers said.
Paxil did appear to triple the risk of a defect in blood flow from the heart, both studies found. But that additional danger would still be modest, experts said.

The studies further hinted at possible ties between other SSRIs and a handful of other defects, but researchers said the numbers of newborns with specific defects were too small to draw strong conclusions.

“Based on these studies, it’s correct to say: no major risk,” said Carol Louik, a public health expert who led the Boston study. “I wouldn’t say, ‘No risk.’”

Researchers said women should talk over the potential risks and benefits with their doctors, preferably before pregnancy.

(Associated Press)