Maternal use of hormonal contraception and risk of childhood ADHD: a nationwide population-based cohort study

We examined the association between maternal hormonal contraception use before or during pregnancy and ADHD risk in children. This nationwide population-based cohort study included 1,056,846 children born in Denmark between 1998 and 2014. Prescriptions for hormonal contraceptives redeemed by the mother was categorized as: no use, previous use (>  3 months before pregnancy), and recent use (≤ 3 months before or during pregnancy). Children were followed for ADHD, from birth until 31 December 2015. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). During 9,819,565 person-years of follow-up (median: 9.2), ADHD was diagnosed or a prescription for ADHD medication redeemed for 23,380 children (2.2%). The adjusted HR for ADHD was higher in children of mothers who had previously (HR 1.23; 95% CI 1.18–1.28) or recently (HR 1.30; 95% CI 1.24–1.37) used hormonal contraception than in those of mothers with no use. The highest estimates were seen for use of non-oral progestin products with HRs of 1.90 (95% CI 1.59–2.26) for previous use, 2.23 (95% CI 1.96–2.54) for recent use, and 3.10 (95% CI 1.62–5.91) for use during pregnancy. Maternal use of hormonal contracepti on was associated with an increased risk for ADHD in the offspring; more pronounced for non-oral progestin-only than other products.
Source: European Journal of Epidemiology - Category: Epidemiology Source Type: research