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Birth-Defect Risk From Antidepressants Is Seen as SmallJuly 16, 2015
Study finds limited associations with Paxil and Prozac, and no links to some other drugs.
The risk of some birth defects increases just slightly when pregnant women take certain antidepressants, according to a large study published Wednesday that sheds new light on a much-debated topic.
The study, published in BMJ, a medical journal, found associations between certain birth defects and two antidepressants—Prozac, or fluoxetine, and Paxil, or paroxetine—taken in the month before pregnancy and through the first trimester.
But it found no such links with three other antidepressants: Zoloft, or sertraline, the drug taken by most participants in the study’s control group, who were in treatment for depression, as well as Celexa, or citalopram, and Lexapro, or escitalopram.
All of those drugs are from the most common class of antidepressants, known as selective serotonin reuptake inhibitors. Whether SSRIs are linked to neural tube defects, cardiac malformations and other rare disorders in babies has been a matter of debate for years. Studies have reached conflicting conclusions.
In 2005, the Food and Drug Administration warned that Paxil could increase the risk for birth defects, and heart defects in particular.
A study published last month found that use of antidepressants late in pregnancy may be associated with increased risk of a serious respiratory disorder known as persistent pulmonary hypertension of the newborn, or PPHN. But the increased risk appeared to be less than previously thought.
Antidepressants are some of the most commonly prescribed drugs in the U.S. About one in 10 Americans aged 12 and older takes one, according to estimates by the Centers for Disease Control and Prevention. Many pregnant women need antidepressants, researchers and mental-health experts say, noting that stopping them during pregnancy could be more dangerous for women who are severely depressed.
In the latest research, a team of U.S. and Canadian researchers, led by the CDC, analyzed results from previous studies and combined them with data from the National Birth Defects Prevention Study, a population-based U.S. study that includes more than 30 categories of major birth defects. Their analysis included 17,952 mothers of infants with birth defects, and 9,857 mothers of infants without birth defects, born between 1997 and 2009.
The researchers found associations between fluoxetine and defects in the heart wall as well as craniosynostosis, or irregular skull shape. Five birth defects were linked to paroxetine, including heart defects; anencephaly, defined as problems with brain and skull formation; and abdominal-wall defects.
But the increase in absolute risk was small, they said. For example, the risk of anencephaly in the children of women taking paroxetine would be seven in 10,000 instead of two in 10,000. For one of the heart defects, the risk rises to 24 in 10,000 from 10 in 10,000. Overall, the risk of having a baby with a birth defect is about 3%, the CDC says.
While previous studies have reported five associations between sertraline and birth defects, the authors of this study found none, a development they called “reassuring.” Nor did they find evidence of other previously reported links between the use of SSRIs in early pregnancy and infant birth defects.
Jennita Reefhuis, a CDC epidemiologist and lead author of the study, said the goal is to help women and doctors identify the safest medications to take during pregnancy, something it does with a program called “Treating for Two.” “It’s important to look at all the treatment possibilities and see if we can find a distinction in terms of how much risk there is,” she said. The CDC plans to use its birth-defects data to examine all birth defects and SSRIs, she said.
Christina Chambers, a professor of pediatrics at the University of California, San Diego who helps lead a network that provides information about the safety of medications in pregnancy, said the study was one of a few that was large enough to examine specific antidepressants. Dr. Chambers wasn’t involved in the latest study. “This study is useful in terms of trying to nail down more precisely risks associated with specific drugs and specific birth defects,” she said. “What patients want.