A Cohort Study of Psychotropic Prescription Drug Use in Pregnancy in British Columbia, Canada from 1997 to 2010

Background: Psychiatric conditions are relatively common during pregnancy, and many of these conditions are treated with psychotropic medications. In this article, we aim to quantify the rate of pregnancy-related exposures and describe how psychotropic medications are being used in pregnancy. Methods: We conducted a retrospective cohort study of all pregnancies ending in a live birth in the Canadian province of British Columbia between January 1, 1997 and December 31, 2010. We examined antipsychotic, anxiolytic, antidepressant, and stimulants use during pregnancy. We describe use of these medications across the pregnancy period, in terms of incident and prevalent use in pregnancy and whether women had corresponding diagnoses for mental health conditions. Results: We included 424,307 pregnancies, of whom 7.1% were dispensed a psychotropic medication. The most commonly used psychotropic medications were antidepressants (4.2%) followed by anxiolytics (3.4%). Among psychotropic medication users, the most commonly associated psychiatric diagnosis was major depressive disorder (43.2%) followed by anxiety (15.8%) and adjustment reaction and/or acute stress (15.8%). The majority of antidepressant use was prevalent (continued from preconception period), whereas most anxiolytic use was incident (no prescriptions in the 6 months before conception). Conclusions: The relatively high rate of use of psychotropic drugs in this cohort, and the existence of effective alternative treatments for the commonly treated conditions suggests a need to improve access to nondrug options before and during pregnancy. The finding that fewer women are discontinuing their antidepressants during pregnancy should be further investigated.