Trends and patterns of antipsychotic medication use during pregnancy: A population‐based study

Aim The prescription of antipsychotic medication during pregnancy, particularly second‐generation antipsychotics, has increased in several countries in recent decades. This population‐based study investigated trends and patterns in antipsychotic medication use during pregnancy between 2011 and 2023 in Northern Ireland (NI), UK. The purpose was to improve understanding about how these medicines are used during pregnancy, including patterns of antipsychotic discontinuation across pregnancy. Methods Data from the Northern Ireland Maternity System (NIMATS) were linked to dispensed prescribing data from the Enhanced Prescribing Database (EPD) and the NI Multiple Deprivation Measure 2017 (NIMDM). Overall temporal trends were identified, and subsequently stratified by subtype (first‐ and second‐generation antipsychotics [FGAs and SGAs]). Usage was evaluated by pregnancy exposure period (12 weeks before pregnancy and by trimester). A separate analysis investigated patterns across trimesters in women who had been dispensed antipsychotics 12 weeks before pregnancy, including concomitant dispensing of antidepressants. Results The cohort included 287 757 singleton pregnancies in 175 938 women aged over 16 years, with an overall prevalence of antipsychotic use of 79.9 per 10 000 pregnancies. The prevalence of antipsychotic usage increased by 71% from 59 to 101 per 10 000 pregnancies between 2011 and 2023 ( p = .001). SGA usage almost tripled from 32 to 93 per 10 000 pregnancies, whereas FGA usage decreased by 73% from 30 to 8 per 10 000 pregnancies in 2011 compared with 2023. Overall usage of antipsychotics decreased across trimesters. Conclusion Overall antipsychotic prevalence during pregnancy increased over the study period, most notably SGA usage, whereas FGA usage decreased.