Profiles of polysubstance exposure in youth with fetal alcohol spectrum disorders and the association with neurodevelopmental outcomes.

BACKGROUND

Prenatal polysubstance exposure is highly prevalent among individuals with fetal alcohol spectrum disorders (FASD), yet little research has examined how specific patterns of co-exposure relate to neuropsychological outcomes. While alcohol is a known teratogen, other substances such as opioids, stimulants, cannabis, and nicotine also disrupt neurodevelopmental processes. Prior studies often assess single substances in isolation, failing to reflect real-world exposure patterns. Identifying meaningful patterns of co-occurring exposures and their associations with neuropsychological outcomes is critical for advancing targeted assessment and intervention.

METHODS

Latent class analysis was conducted on data from 635 youth with FASD (mean age of diagnosis 7.4 years, range 0.24-21.61) to identify distinct profiles of prenatal exposure to six substances: alcohol, nicotine, marijuana, opioids, cocaine, and other drugs. Class differences in neuropsychological functioning, postnatal experiences, and demographics were examined using the Bolck, Croon, and Hagenaars method.

RESULTS

A three-class solution demonstrated best model fit (AIC = 3945.216, saBIC = 3970.790, aLRT = 18.521, p = .006). Classes comprised of an all-exposure (Class 1, 47%), mainly alcohol exposed (Class 2, 46%), and mainly opioid exposed (Class 3, 7%). Significant between-class differences emerged across domains of memory, motor speed, sensory processing, and child-reported anxiety (χ2 = 9.264-42.659, p = .046-0.001). Class 2 demonstrated significantly greater neuropsychological challenges, while Class 3 demonstrated high sensory sensitivity and anxiety. Results also reveal caregiver disruption was more prevalent in Class 2.

DISCUSSION: Findings highlight heterogeneity in neuropsychological outcomes based on distinct patterns of prenatal polysubstance exposures. Neuropsychological assessment remains essential for capturing this variability and informing individualized, exposure-responsive care.