No significant link between SSRIs, autism

According to a new Danish study, use of selective serotonin reuptake inhibitors (SSRIs) during pregnancy showed no significant association with autism spectrum disorder (ASD). The study is the largest to date on the potential connection.

Researchers from Statens Serum Institute in Copenhagen studied every singleton live birth in Denmark from 1996 to 2008: 626,875, with follow-up through 2009. Danish population registries were used to identify maternal use of SSRIs before and during pregnancy, ASD diagnosed in the child, and potential confounders.

After 5,057,282 person-years of follow-up, the investigators found 3892 cases of ASD (incidence rate, 77.0 per 100,000 person-years). Fifty-two cases during 42,400 person-years of follow-up involved children of women who had SSRI exposure during pregnancy (incidence rate, 122.6 per 100,000 person-years). When compared with no SSRI use, either before or during pregnancy, SSRI use during pregnancy was not significantly associated with ASD (fully adjusted rate ratio, 1.20, 95% confidence interval [CI], 0.90 to 1.61). The fully adjusted rate ratio was 1.46 (95% CI, 1.17 to 1.81) among women who had SSRI exposure before pregnancy, but no exposure during their pregnancy.

The study authors concluded that there was no significant association between SSRIs and ASD. Because of the confidence interval, however, they indicated that they could not rule out a relative risk up to 1.61 and felt that the association required even further study.

Hviid A, Melbye M, Pasternak B. Use of selective serotonin reuptake inhibitors during pregnancy and risk of autism. N Engl J Med. 2013;369(25):2406–2415.