Neurodevelopmental outcomes following prenatal cannabinoid exposure: a systematic review

Cannabis use during pregnancy is increasing worldwide, yet evidence regarding its long-term neurodevelopmental consequences remains heterogeneous and inconclusive. This systematic review aimed to synthesise observational evidence on the association between prenatal cannabis exposure and neurodevelopmental outcomes from birth to adolescence. A systematic search of PubMed/MEDLINE, Web of Science, and PsycINFO was conducted from database inception to October 2025. Observational studies evaluating neurodevelopmental outcomes following prenatal cannabis exposure were included. Outcomes were grouped by domain and age group. Risk of bias was assessed using the Newcastle-Ottawa Scale. Due to substantial heterogeneity in exposure definitions, outcome measures, and confounder adjustment, findings were synthesised narratively. Seventy-two studies met inclusion criteria. Associations appeared to be domain-specific rather than reflecting global neurodevelopmental impairment. Behavioural dysregulation, attention-related difficulties, and executive functioning showed the most consistent associations with prenatal cannabis exposure, with 73%, 69%, and 70% of studies within these domains reporting negative associations, respectively. In contrast, most studies found no significant associations with global cognition (84%), language (92%), or motor development (60%) after adjustment for confounders. Several cohorts suggested stronger associations with heavier or persistent cannabis exposure after maternal awareness of pregnancy, indicating possible dose-response and timing effects. Current evidence does not consistently support global neurodevelopmental impairment following prenatal cannabis exposure but suggests a pattern of selective vulnerability in behavioural, attention and executive regulatory domains. Together, these findings support cautious clinical counselling and highlight the need for high-quality longitudinal studies with improved exposure and outcome measurements, and rigorous confounder control.