Association of Maternal Use of Benzodiazepines and Z-Hypnotics During Pregnancy With Motor and Communication Skills and Attention-Deficit/Hyperactivity Disorder Symptoms in Preschoolers

Importance The reproductive safety of benzodiazepine/z-hypnotic exposure on child longer-term developmental risks remains unresolved. Objective To quantify the association of motor, communication, and attention-deficit/hyperactivity disorder (ADHD) symptoms in preschoolers with gestational benzodiazepine/z-hypnotic exposure by timing and duration and coexposure to opioids or antidepressants. Design, Setting, and Participants Nationwide, population-based Norwegian Mother and Child Cohort Study, recruiting pregnant women from 1999 to 2008, with child follow-up from ages 6, 18, and 36 months to ages 5, 7, and 8 years. Follow-up of teenagers is ongoing. The study included women with depressive/anxiety (n = 4195), sleeping (n = 5260), or pain-related (n = 26 631) disorders before and/or during pregnancy. Exposures For the timing analyses, children exposed to benzodiazepines/z-hypnotics in midpregnancy (weeks 17-28) or late pregnancy (week 29 or later) vs those born to nonmedicated women. For the duration and coexposure analyses, benzodiazepine/z-hypnotic treatment for multiple 4-week intervals vs 1 and co-use of benzodiazepine/z-hypnotic with opioids or antidepressants vs sole benzodiazepine/z-hypnotic use. Main Outcomes and Measures Parent-reported motor and communication skills (Ages and Stages Questionnaires) and ADHD symptoms (Conners’ Parent Rating Scale–Revised) at child median age of 5.1 years (interquartile range, 5.0-5.3 years) as standardized mean scores. General linear propensity score–adjusted and marginal structural models were fitted. Analyses were stratified by maternal disorder. Results Of 41 146 eligible pregnancy-child dyads, 36 086 children (18 330 boys and 17 756 girls) were included, of whom 283 (0.8%) were prenatally exposed to benzodiazepines/z-hypnotics (134 in the depressive/anxiety, 60 in the sleeping, and 89 in the pain-related disorders). There was no increased risk for greater ADHD symptoms or fine motor deficits after intrauterine benzodiazepine/z-hypnotic exposure at different time points. Children born to women with depressive/anxiety disorders who took benzodiazepines/z-hypnotics in late pregnancy had greater gross motor (weighted β, 0.67; 95% CI, 0.21-1.13) and communication (weighted β, 0.35; 95% CI, 0.04-0.65) deficits than unexposed children. There was no evidence for substantial duration or coexposure associations. Conclusions and Relevance These findings suggest no substantial detrimental risk on child fine motor and ADHD symptoms after prenatal benzodiazepine/z-hypnotic exposure alone or in combination with opioids or antidepressants. Residual confounding by indication and/or a higher drug dose regimen among women with anxiety/depression may explain the moderate association of gross motor and communication deficits with late-pregnancy benzodiazepine/z-hypnotic use