BACKGROUND: Previous studies suggest a possible association between maternal use of selective serotonin-reuptake inhibitors (SSRIs) during early pregnancy and congenital heart defects (CHD). The purpose of this study was to verify this association by using validated data from the Danish EUROCAT Register, and secondary, to investigate whether the risk differs between various socioeconomic groups.

METHODS: We conducted a cohort study based on Danish administrative register data linked with the Danish EUROCAT Register, which includes all CHD diagnosed in live births, fetal deaths and in pregnancies terminated due to congenital anomalies. The study population consisted of all registered pregnancies (n = 72,280) in Funen, Denmark in the period 1995-2008. SSRI-use was assessed using The Danish National Prescription Registry, information on marital status, maternal educational level, income, and country of origin from Statistics Denmark was used as indicators of socioeconomic situation, and the CHD were studied in subgroups defined by EUROCAT. Logistic Regression was used to investigate the association between redeemed prescriptions for SSRIs and CHD.

RESULTS: The risk of severe CHD in the offspring of the 845 pregnant women who used SSRIs during first trimester increased four times (AOR 4.03 (95% CI 1.75-9.26)). We found no increased risk of septal defects. Socioeconomic position did not modify the association between maternal SSRI-use during pregnancy and severe CHD.

CONCLUSION: This study, which is based on data with high case ascertainment, suggests that maternal use of SSRIs during first trimester increases the risk of severe CHD, but does not support findings from previous studies, based on administrative register data, regarding an increased risk of septal defects. The study was unable to document an interaction between socioeconomic status and maternal SSRI-use on the risk of severe CHD.