Psychotropic drug utilization patterns in pregnant women with bipolar disorder: A 16-year population-based cohort study.

Despite growing concern about reproductive safety of psychotropic drugs, there is a paucity of research assessing prenatal prescribing practices for bipolar disorder (BD). This population-based cohort study identified women aged 15-50 years with BD diagnosis, who delivered their first and singleton child between 2003 and 2018 in Hong Kong, with an aim to examine temporal trends and predictors of prenatal psychotropic drug use as well as drug utilization patterns before and during pregnancy were evaluated. Data were retrieved from territory-wide medical-record database of public healthcare services. Of 302 identified women, 202 (66.9%) and 180 (59.6%) redeemed at least 1 prescription for psychotropic drugs in 12 months pre-pregnancy and during pregnancy, respectively. Psychotropic drug treatment (OR = 16.14 [95% CI: 8.79-29.65]) and psychiatric admission (OR = 4.12 [95% CI: 1.66-10.24]) within 12 months pre-pregnancy were associated with prenatal drug use. Second-generation antipsychotic use during pregnancy increased over time, while prenatal use of lithium, anti-epileptics and first-generation-antipsychotics showed declining trend. Use of psychotropic drugs progressively decreased across pre-pregnancy and trimesters of pregnancy. Forty-two (23.3%) women received polypharmacy during pregnancy. Antidepressant use accounted for 17% of all monotherapy episodes. A significant proportion of women exposed to valproate in 12 months pre-pregnancy (27.2%) and first-trimester (16%). In conclusion, our results generally indicate trajectories of reduced psychotropic drug use across pregnancy. Deviations between real-world prescribing patterns and treatment guidelines underscore the need for comprehensive review of current clinical practices. Further research clarifying relationships of prenatal psychotropic drug exposure with maternal and fetal outcomes is warranted.