Maternal Substance Use Disorders and Accidental Drug Poisonings in Children.

INTRODUCTION

Risk factors for accidental drug poisonings in children are poorly understood, including the association with maternal substance use. This study seeks to determine whether maternal substance use disorders before birth are associated with the future risk of accidental drug poisonings in young children.

METHODS

This study was a longitudinal cohort analysis of 1,032,209 children aged <5 years between 2006 and 2020 in Quebec, Canada. The main exposure included maternal substance use disorders before or during pregnancy. The outcome was hospitalization for drug poisonings before age 5 years, including opioids, cannabis, sedatives/hypnotics, stimulants, and other drugs. Adjusted Cox proportional hazards regression was used to compute hazard ratios and 95% CIs for the association of substance use disorders with child drug poisonings during 4,523,003 person-years of follow-up. Analyses were conducted in 2020.

RESULTS

Hospitalization rates for drug poisoning before age 5 years were greater for children of mothers with substance use disorders versus no substance use disorder (84.8 vs 20.7 per 100,000 person-years). Maternal substance use disorders before birth were associated with 2.28 times the risk of future drug poisonings in children (95% CI=1.63, 3.20). The association was stronger for maternal opioid use disorders (hazard ratio=4.16, 95% CI=2.38, 7.27) than other drug use disorders. Associations with child poisonings were stronger between age 1 and 2 years (hazard ratio=3.26, 95% CI=2.09, 5.10) and for poisonings involving opioids, cannabis, and sedative/hypnotic drugs.

CONCLUSIONS

Maternal substance use disorders before childbirth may be markers of future risk of drug poisonings in young children.