Time trends in maternal attention-deficit/hyperactivity disorder and medication use in pregnancy

Background — Attention-deficit/hyperactivity disorder (ADHD) is increasingly recognized among women of reproductive age. Little is known about time trends in maternal ADHD, and treatment utilization in this group.

Methods — We conducted a cross-sectional time series analysis of all obstetrical deliveries in Ontario, Canada, from 2002–2023 (medication data available from 2014). Maternal ADHD was defined by inpatient or outpatient diagnosis within 10 years preconception. Stimulant medication use (amphetamine, dextroamphetamine, lisdexamfetamine, methylphenidate) was assessed via prescription fills in the year before pregnancy, during pregnancy, and stratified by trimester. We described the annual proportions of pregnancies with preconception maternal ADHD diagnoses and stimulant use patterns in this group.

Results — Of 2,327,110 included pregnancies, the proportion of pregnancies with maternal ADHD rose from 0.5% to 2.5% from 2002 to 2023. Between 2014 and 2023, stimulant use increased from 21.8% to 39.8% in the year prior to pregnancy and from 10.1% to 20.9% during pregnancy among those with ADHD. Methylphenidate predominated early in the study period, but increases over time were largely driven by lisdexamfetamine. Approximately 75% of those prescribed a stimulant in the year prior to conception discontinued it prior to, or in, the first trimester of pregnancy, with stable time trends.

Conclusions — The 4-fold increase in maternal ADHD in pregnancy over a 20-year period and 2-fold increase in the use of stimulant medication before and during pregnancy in this group underline the need for clinical guidance on managing ADHD in pregnancy.