Background: There is a need for case-control studies of the effect of paroxetine on the occurrence of specific heart defects.
Methods: We performed a case-control study with data from a population-based birth defects registry in the Netherlands. All the children born between 1997 and 2006 were selected. Cases were defined as fetuses and children with isolated heart defects, and the controls were fetuses and children with a genetic disorder with no heart defect. We excluded children for whom there was no information on maternal medication use and deceased children and fetuses who were not examined postmortem. First-trimester exposure to paroxetine was compared between cases and controls by calculating adjusted odds ratios (AOR).
Results: We included 678 cases with isolated heart defects and 615 controls. The first trimester exposure rate was 1.5% for cases and 1.0% for controls. After excluding mothers who used paroxetine outside the first trimester, or who had used another SSRI, we found no significantly increased risk for heart defects overall (10 exposed cases; AOR, 1.5; 95% confidence interval [CI], 0.5-4.0), but we did find a significantly increased risk for atrium septum defects (three exposed cases; AOR, 5.7; 95% CI, 1.4-23.7).
Conclusions: Our results suggest that the use of paroxetine in early pregnancy is associated with an increased risk of atrium septum defects. The results stress the importance of studying possible teratogenic effects of a drug, preferably in regard to well-specified malformations.