Duloxetine Exposure During Pregnancy and the Risk of Spontaneous and Elective Abortion: A Danish Nationwide Observational Study

BACKGROUND: Depression and antidepressant treatment are widespread among women of childbearing age. OBJECTIVE: This study evaluates the association between duloxetine exposure during pregnancy and spontaneous and elective abortions. PATIENTS AND METHODS: The nationwide, observational study based on register data from Denmark included women with a recorded pregnancy in the birth register or an abortion in the patient register between 2004 and 2016. Duloxetine-exposed women were compared with (1) duloxetine non-exposed, (2) selective serotonin reuptake inhibitor (SSRI)-exposed, (3) venlafaxine-exposed, and (4) women discontinuing duloxetine before pregnancy. Exposure status was based on records of redeemed prescriptions. Cox regression with adjustments and propensity score matching was applied. RESULTS: The data from 1,019,957 pregnancies were used, including 1,212 pregnancies exposed to duloxetine. Duloxetine-exposed women had an increased hazard ratio (HR) for spontaneous abortions compared with SSRI-exposed women: propensity score matched HR 1.25 [95% confidence interval (CI), 1.00–1.57]. No increased hazard was observed for duloxetine-exposed women compared with duloxetine non-exposed: 1.08 (95% CI 0.89–1.31); venlafaxine-exposed: 1.08 (95% CI 0.82–1.41); and duloxetine discontinuers: 0.99 (95% CI 0.76–1.30). An increased HR of elective abortions was observed in duloxetine-exposed women compared to duloxetine non-exposed: 1.41 (95% CI 1.25–1.59); SSRI-exposed: 1.32 (95% CI 1.15–1.51); and duloxetine discontinuers: 1.46 (95% CI 1.23–1.75), but not to venlafaxine-exposed women: 1.09 (95% CI 0.93–1.27). CONCLUSION: There was no increased risk of spontaneous or elective abortion associated with exposure to duloxetine. The increase risk observed for women exposed to duloxetine in comparison with SSRI-exposed for spontaneous and in comparison with all groups (except venlafaxine-exposed) for elective abortion suggested confounding. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40801-021-00252-9.