A team from the Ottawa Health Research Institute, the University of Ottawa, and The Ottawa Hospital has found an increased risk of premature delivery, low birth weight, fetal death, and infant seizures among pregnant women who used a popular class of antidepressants during pregnancy.
The study, published in the April issue of the American Journal of Obstetrics and Gynecology, uses linked maternal / infant prescription and health records to assess the safety of a class of antidepressants known as selective serotonin re-uptake inhibitors (SSRIs). Records were obtained for 972 pregnant women taking SSRIs and 3,878 matched controls not taking SSRIs. The investigators found that the SSRI group had a significantly increased risk of premature birth (19.3 per cent versus 12.0 per cent), low birth weight (9.0 per cent versus 5.3 per cent), fetal death (1.1 per cent versus 0.4 per cent) and infant seizures (0.4 per cent versus 0.1 per cent). There was no increased risk of birth defects, infection, need for respiratory support, or death up to one year after birth.
While previous studies have reported side effects of SSRIs on the developing fetus, this investigation is the largest ever to examine such a wide variety of effects without relying on patient memory for prescription records.
"These results are certainly unsettling," said Dr. Mark Walker, a Scientist at the Ottawa Health Research Institute and one of the study's lead authors. "But untreated depression has also been shown to have side effects on women, and possibly on their fetuses. I feel that it is important that every case be individually assessed to determine the risks and benefits of antidepressant therapy. Patients need to make informed decisions and for those women on SSRIs, we should increase our surveillance." Dr. Walker is also a physician in the Department of Obstetrics and Gynecology at The Ottawa Hospital and an Associate Professor in the Faculty of Medicine at the University of Ottawa.
The study included SSRIs such as fluoxetine (Prozac) Paroxetine (Paxil) and Sertraline (Zoloft), but the sample size was not large enough to estimate risks for each SSRI individually.