RESEARCH ARTICLE Trends and Determinants of Prescription Drug Use during Pregnancy and Postpartum in British Columbia, 2002–2011: A Population-Based Cohort Study

Purpose To describe trends, patterns, and determinants of prescription drug use during pregnancy and postpartum. Methods This is a retrospective, population-based study of all women who gave birth between Janu-ary 2002 and 31 December 2011 in British Columbia, Canada. Study population consisted of 225,973 women who had 322,219 pregnancies. We examined administrative datasets containing person-specific information on filled prescriptions, hospitalizations, and medical services. Main outcome measures were filled prescriptions during pregnancy and postpar-tum. We used logistic regressions to examine associations between prescription drug use and maternal characteristics. Results Approximately two thirds of women filled a prescription during pregnancy, increasing from 60 % in 2002 to 66 % in 2011. The proportion of pregnant women using medicines in all thre