Neurobehavioral disorders among children born to mothers exposed to illicit substances during pregnancy

Background Preventions may be schemed if pregnant mothers’ exposure status of substance use is associated with neurodevelopmental conditions. This study explores subsequent risks for intellectual disability, autistic disorders, and attention deficit and hyperactivity disorders in children born to mothers exposed to illicit substances before or during pregnancy. Method We identified women with illicit drug use by linking the police records from the ‘Substance Abuse Control Databases’ and Taiwan Birth Registration and Birth Notification records from 2004 to 2014. Children born by mothers identified from the police records were the ‘substance-exposed cohort’. A 1:1 child’s gender, child’s birth year, mother’s birth year, and child’s first use of the health insurance card exact matched comparison cohort and another ‘propensity score (PS)- matched’ comparison cohort of children born by substance-unexposed mothers were established. Multivariate Cox regression analyses with competing risk models were performed. Results Higher incidences of intellectual disability (aHR = 2.41, 95% CI: 1.15 ~ 5.03) and ADHD (aHR = 2.35, 95% CI: 1.63 ~ 3.28) were found in children born by mothers exposed to illicit substances during pregnancy compared to exact- matched non-exposed cohorts. Adjusted risks of ADHD were significantly higher in mothers exposed to substances during pregnancy (aHR = 1.77(1.42 ~ 2.21) and before pregnancy (aHR = 1.43 (1.14 ~ 1.80) compared to PS-matched unexposed cohorts after adjusting for covariates. Conclusions and Relevance This is the first study that used large population-based data that revealed overall increased risks of intellectual disability and ADHD in children with prenatal exposures of illicit substances compared to those exact and propensity scores matched unexposed controls. The attenuation of such excessive hazards after adjusting for covariates of preterm birth, low birth weight, and fifth-minute APGAR score might reflect that enhanced antepartum screening and appropriate medical care may help prevent subsequent neurobehavioral disorders.