Antidepressant tied to risk of newborn heart defect

Women who use the antidepressant bupropion during early pregnancy may have an increased risk of having a baby with a particular type of heart defect, a new study suggests.

Researchers caution that it is not clear whether the medication, marketed as Wellbutrin, is the cause. And even if it is, they say, the absolute risk of the heart defect would be small - affecting just 2 out of every 1,000 infants born to women who used bupropion during the first trimester.

But the findings, published in the American Journal of Obstetrics & Gynecology, do add to questions about the risks of using antidepressants during early pregnancy.

Some studies have already linked other antidepressants - including some of the commonly used selective serotonin reuptake inhibitors (SSRIs) - to higher-than-average, though small, risks of certain birth defects.

A study last year, for example, found that among nearly half a million Danish children born between 1996 and 2003, the risk of heart defects was elevated among those whose mothers had used SSRIs such as fluoxetine (Prozac), sertraline (Zoloft) and citalopram (Celexa) during early pregnancy.

In this latest study, researchers found that among more than 12,700 U.S. infants born between 1997 and 2004, those whose mothers used bupropion during early pregnancy had more than double the risk of heart defects known as left outflow tract defects, compared with infants whose mothers had not used the drug.

Left outflow defects affect the flow of blood from the heart's left chambers to the rest of the body. In this study, the most common type of this defect was coarctation of the aorta - a narrowing in the body's main artery that, in children, typically requires surgical repair.

The findings do not mean, however, that depressed women on bupropion should stop taking it if they are planning a pregnancy, according to the researchers.

"I think it's important that women understand that they should not just stop taking their medication," said Dr. Jennita Reefhuis, a senior epidemiologist at the U.S. Centers for Disease Control and Prevention and one of the researchers on the study.

Instead, she told Reuters Health, women should talk with their doctors, ideally when they are planning a pregnancy rather than after they conceive.

The potential risk of birth defects from using antidepressants must be weighed against the risks of a woman stopping her current depression therapy, Reefhuis said.

For the study, Reefhuis and her colleagues used data on 6,853 infants born with a major heart defect and 5,869 infants with no birth defects. Of mothers whose babies were born with a heart defect, 0.5 percent reported using bupropion at some point in the month before becoming pregnant or the first trimester.

There were 10 cases of left outflow tract heart defects among mothers who had used bupropion. The drug was not linked to any other type of heart defect.