048 - Extent of Prenatal Drug Exposure Predicts Cognitive Outcome in Early and Middle Childhood

Publication Number: 48.4916

Samantha J. Lee, University of Canterbury, Christchurch, Canterbury, New Zealand; Megan Gath, University of Canterbury, Christchurch, Canterbury, New Zealand; Nicola Austin, Christchurch Women's Hospital, Christchurch, Canterbury, New Zealand; Lianne J. Woodward, University of Canterbury, Christchurch, Canterbury, New Zealand

Background: The misuse of licit and illicit substances during pregnancy is of major public health concern and has escalated with the recent opioid epidemic. Prenatal exposure to a range of substances has been linked with increased child developmental risk. However, few studies have involved long-term follow-up, leaving cognitive outcomes beyond early childhood poorly understood.

Objective: 1) Characterize the cognitive development from ages 4.5 to 9.5 years of children exposed prenatally to opioids and other substances (POE) and non-opioid-exposed children 2) Examine the extent to which exposure to various substances, neonatal factors, and the postnatal family environment predicted cognitive outcome within the POE group.

Design/Methods: Participants were a regionally representative cohort of children (N=100) born to women who were polysubstance-using and were in medication-assisted treatment for opioid use disorder during pregnancy. They were studied prospectively to age 9.5 years alongside a group of 110 non-opioid-exposed comparison children (87% retention). At 4.5 and 9.5 years, short forms of the Wechsler Intelligence Scales (WPPSI-R, WASI-II) were administered. Extensive data describing children’s prenatal environment, neonatal clinical course, and family social circumstances were collected, with the Home Observation for Measurement of the Environment (HOME) coded based on an 18-month home visit.

Results: Children in the POE group had lower IQ scores than comparison children at both 4.5 (M=98 vs.112, p<.001) and 9.5 years (M=94 vs. 108, p<.001; Table 1). Across both ages, around a third of POE children met criteria for cognitive delay relative to controls (36-37% vs. 9%, p<.001). However, within the POE group, rates of severe cognitive delay increased with age, from 9% of those with any delay at age 4.5 to 58% at age 9.5 years. Key predictors of child IQ in the POE group were third trimester methadone dose (p=.07), prenatal nicotine exposure (p=.03), prenatal benzodiazepine exposure (p=.07) length of hospital stay (p=.04), and total HOME score (p=.03; Table 2).

Conclusion(s): Children born to women with an opioid use disorder are at increased risk of delayed cognitive development to middle childhood. Children most at risk were those born to mothers with increased polysubstance use (especially opioids, nicotine, benzos) with a slower neonatal transition, and then exposed postnatally to poorer quality early home environments. These findings underscore the importance of ongoing support and intervention for this vulnerable population to mitigate the long-term effects of prenatal substance exposure on development.

Table 1. Cognitive Outcomes at Ages 4.5 and 9.5 Years for Children with Prenatal Opioid and Polysubstance Exposure and Non-Opioid-Exposed Comparison Children


Table 2. Fixed Effects Estimates from Linear Mixed Models Predicting IQ Scores at Ages 4.5 and 9.5 for Children with Prenatal Drug Exposure