September 11, 2014 — Taking a common form of antidepressants -- called selective serotonin reuptake inhibitors -- early in pregnancy likely does not increase the risk of miscarriage, according to a study published in Obstetrics & Gynecology, HealthDay/U.S. News & World Report reports.
Other studies have suggested that women who take SSRIs in pregnancy have a higher risk of miscarriage and other pregnancy complications, but they were not designed to assess whether there is a causal relationship (Norton, HealthDay/U.S. News & World Report, 9/9).
For the new study, researchers analyzed data on more than 1.2 million pregnant women using 1997 to 2010 data from Denmark's medical registry.
The researchers compared pregnancy outcomes for women who had not been prescribed SRRIs, women who stopped receiving SSRIs prescriptions three to 12 months prior to pregnancy and women who were prescribed SSRIs during the first 35 days of pregnancy. The researchers adjusted the data for several factors, including age, education, income and previous miscarriages (Osterweil, Medscape, 9/9).
Compared with women who were never prescribed SSRIs, the increased risk of miscarriage was similar -- about 27% -- among women whose SSRI prescriptions stopped at least three months before they became pregnant and those who were prescribed the drugs during the first trimester, the study found.
Study lead author Jon Andersen said the "results clearly indicate that miscarriage is not associated with SSRIs, but with conditions associated with the use of SSRIs" (HealthDay/U.S. News & World Report, 9/9).
The authors wrote, "The increased risk of miscarriage in our study may be explained by the underlying illness or lifestyle factors such as alcohol use, smoking, or poor compliance to folic acid supplementation during pregnancy" (Medscape, 9/9).
Other Experts React
Adam Urato -- a maternal-fetal medicine specialist at Tufts Medical Center -- expressed skepticism about the authors' conclusions, arguing that because the study relied on prescribing data, it was not possible to determine if the women actually took the drugs. He added that the study's findings should be interpreted within the context of other studies that have suggested SSRIs themselves might increase miscarriage risk.
Meanwhile, Christina Chambers -- director of the Center for the Promotion of Maternal Health and Infant Development at the University of California-San Diego -- called the study's conclusions "reasonable," adding that previous studies had shown that SRRIs had led to a "modest" increase in risk of a miscarriage. She noted that women should weigh the potential risks of taking SSRIs with the risks of deciding to stop taking them (HealthDay/U.S. News & World Report, 9/9).