Abstract
Background As cannabis use becomes more common worldwide, an increase in its use is also observed among women of reproductive age, including during pregnancy. Several studies examined the possible impact of prenatal cannabis exposure on children’s psychiatric and neurobehavioral development. However, the variability and inconsistency in the associations observed make it difficult to fully evaluate the risks and potential harm of in-utero cannabis exposure. Therefore, our objective is to evaluate the existing data and assess the association between cannabis exposure during pregnancy and the risk for neuropsychiatric outcomes in the offspring.
Methods We followed the PRISMA 2020 guidelines for systematic review and meta-analysis. MEDLINE, EMBASE, and Cochrane databases were searched up to August 2022. Data were independently screened for eligibility and extracted by two reviewers. Studies were eligible for inclusion if they reported quantitative data on long-term neuropsychiatric outcomes in the offspring prenatally exposed to cannabis versus control. Data were pooled using random-effects models.
Results Fourteen eligible observational studies were included in the review, and twelve were included in the final quantitative analysis. The pooled odds ratio (OR( for ADHD was 1.12 (95% confidence interval (CI): 1.00–1.27); for ASD, the pooled risk ratio (RR) was 1.18 (95% CI 0.7–1.97); for psychotic symptoms, the pooled RR was 1.18 (95% CI 0.95–1.45); for anxiety, the pooled OR was 1.63 (95% CI 0.78–3.40); and for offspring’s marijuana use the pooled OR was 1.2 (1.01–1.42).
Conclusions There was no association between exposure to cannabis during pregnancy and ADHD, ASD, psychotic symptoms anxiety in the offspring. The association between prenatal cannabis exposure and the mildly increased risk for ADHD might be due to residual confounding and not because of the exposure. These results should be interpreted with caution, given the observational nature of the studies and the potential for residual confounding.