SSRI Antidepressants May Pose Birth Defect, Autism RisksJul 19, 2011 | Parker Waichman LLP
SSRI (selective serotonin reuptake inhibitor) antidepressants taken during pregnancy may make it more likely that a baby will be born with heart birth defects or autism, according to a pair of recent studies. The author of one of the studies cautioned that the drugs, which include those sold under the brand names Lexapro, Paxil, Prozac, Wellbutrin, Zoloft, Zyban, Effexor and Luvox, should only be used during pregnancy when clearly indicated.
The U.S. Food & Drug Administration (FDA) has placed most SSRIs in Pregnancy Category C, a classification that means they have been linked with birth defects in animal studies, but have not been proved safe or unsafe in humans because few studies have been conducted. However, Paxil has been deemed Category D, which is assigned to medicines that have been shown to present a risk to the fetus in studies of pregnant women, but may still offer benefits that outweigh the risks the drug presents.
The study that found a link between cardiac birth defects and SSRI antidepressants is published in the July issue of the journal Obstetrics & Gynecology. The researchers conducted data on about 635,583 births that occurred between 1996 and 2006. Out of 10,000 women who took Paxil, 31 had a heart defect, compared to only seven among the same number of babies born to women who did not take the drug. Of 10,000 babies exposed to Prozac before birth, 105 developed a heart defect. Only 49 suffered a similar problem among the 10,000 who were not exposed.
Other birth defect risks also showed up in the study. Twenty-two out of 10,000 exposed babies were born with a neural tube defect, versus only 9 out of 10,000 babies born to moms who didn't take SSRIs.
The second study, which appears in the Archives of General Psychiatry, found that children exposed to SSRI antidepressants before birth during the first trimester were nearly four times as likely to develop an autism spectrum disorder (ASD) compared with unexposed children. The study looked at 300 children with ASD, and found that 6.7 percent were exposed to SSRIs in the womb, compared with 3.3 percent of the control children. After accounting for other factors that could impact pregnancy outcomes, the researchers calculated that any fetal exposure to SSRIs increased the risk of ASD diagnosis 2.2-fold, while first-trimester exposure increased the risk 3.8-fold.
Considering those odds, 2 percent of all autism cases among children born in the late 1990s could be attributed to SSRI exposure, the researchers estimate. The percentage would be higher today because more women take the drugs during pregnancy.
They did caution, however, that their study - the first to look at a possible SSRI -autism link - was small. The results need to be confirmed by larger studies.