Prenatal antidepressant utilization and trajectories in Switzerland using the MAMA cohort

Affective disorders are common during pregnancy and guidelines recommend continued use of antidepressants during pregnancy. Trajectories of antidepressant treatment during pregnancy and the prevalence of prenatal exposure to antidepressants in Switzerland remains understudied. This study aimed: 1) to estimate the prevalence of prenatal antidepressant dispensation and of four predefined treatment patterns (continuation, switch, discontinuation and restart); 2) to identify trajectories of antidepressant dispensation from 9 months before pregnancy to delivery.

Using Swiss claims data from 2010 to 2019, we estimated the prevalence of antidepressant dispensation during pregnancy and of the treatment patterns. We identified trajectories of antidepressant medication using group-based trajectory modeling (GBTM). To better characterize the trajectories, we tested their associations with comedications and other covariates.

Among 84,317 pregnancies, 1.6 % (95 % CI = [1.5 %, 1.7 %]) were exposed to antidepressants. Prevalence of treatment patterns ranged from 0.02 % to 0.40 %. Discontinuation and restart accounted for 9.6 % and 4.5 % of pregnancies with antidepressant dispensations. GBTM resulted in six trajectories: GBTM-increase over pregnancy (11.3 % of the women using antidepressants), GBTM-discontinuation (11.4 %), GBTM-continuation (4.6 %), GBTM-discontinuation before pregnancy (16.4 %), GBTM-episodic dispensation (44.4 %) and GBTM-decrease over pregnancy (11.9 %). Anxiolytic and antipsychotic use was frequent among GBTM-continuation and GBTM-restart before pregnancy.

The prevalence of antidepressant dispensation during pregnancy was similar to the prevalence in Europe. The most prevalent trajectory was episodic dispensation and a fifth of women stopped antidepressants before pregnancy and another fifth during pregnancy, which is not in line with recommendations. Future studies should investigate patient and clinician level reasons for discontinuation.