Women of childbearing age often suffer from depression. In most patients, the first-line medications for the treatment of depression are selective serotonin reuptake inhibitors (SSRIs). Currently, the risk that SSRIs pose to the fetus during pregnancy has not been well established. The U.S. Food and Drug Administration labels this class of medications as category C, meaning animal studies have discovered adverse fetal effects, but there are no controlled studies in pregnant women. Previous studies have suggested that SSRIs may cause neonatal withdrawal syndrome, low birth weight, and preterm birth, and those that have evaluated the possible teratogenic effects of SSRIs have had inconsistent findings. Wen and colleagues conducted a population-based study to evaluate the safety of SSRIs in pregnancy and during the preconception period.

The authors conducted a retrospective cohort study of database records of pregnant women in a Canadian province who gave birth between January 1, 1990, and December 31, 2000. This database included prescribing information for more than 90 percent of the residents who were provided prescriptions during the study. There were two groups established from the data. The first group included women who were prescribed at least one SSRI within one year of giving birth and were labeled as the “exposed” group. The control group was selected by matching the year of birth, type of birthing institution, and geographic location to the exposed group. Data collected for each group included adverse pregnancy outcomes, major and minor birth defects, fetal death, severe neonatal morbidity, and infant death.

There were 972 pregnant women in the exposed group and 3,878 in the control group. There were five SSRIs used by women during the study, with fluoxetine (Prozac) being the most common. When compared with the control group, those who used SSRIs during pregnancy were more likely to have infants with low birth weight, neonatal seizures, preterm birth, and fetal death. There were no significant differences between the two groups when comparing major or minor birth defects in newborns. In addition, there were no significant differences in maternal complications between the two groups.

The authors conclude that SSRI use during pregnancy may increase the risk of low birth weight, seizures, preterm birth, and fetal death. They add that women should be informed of the potential adverse effects of these drugs during pregnancy, and risk versus benefits should be assessed for each individual.