Clinical Takeaway
Children born to mothers who used cannabis during pregnancy showed a small but measurable increase in risk for both autism spectrum disorder and ADHD, based on pooled data from 13 observational studies. THC and other cannabinoids cross the placenta and can interact with receptors involved in fetal brain development, providing a plausible biological basis for these findings. These results support clinical guidance recommending that cannabis use be avoided throughout pregnancy.
#15 Maternal Cannabis Use in Pregnancy and Autism Spectrum Disorder or Attention-Deficit/Hyperactivity Disorder in Offspring.
Citation: Andrade Chittaranjan. Maternal Cannabis Use in Pregnancy and Autism Spectrum Disorder or Attention-Deficit/Hyperactivity Disorder in Offspring.. The Journal of clinical psychiatry. 2024. PMID: 39724097.
Design: 6 Journal: 0 N: 2 Recency: 1 Pop: 3 Human: 1 Risk: -2
Maternal cannabis use during pregnancy affects up to 10% of pregnant women, and this study provides synthesized evidence that gestational exposure is associated with a 30% increased risk of autism spectrum disorder in offspring, establishing a quantifiable neurodevelopmental concern that warrants clinical counseling and risk stratification. Given the increasing normalization and legalization of cannabis, these findings are clinically significant for prenatal care providers who must counsel pregnant patients about teratogenic risks and for public health initiatives addressing substance use in pregnancy. The mechanistic plausibility through placental cannabinoid receptor signaling combined with the epidemiological association creates an evidence base for clinicians to recommend abstinence during pregnancy until safety thresholds are definitively
Quality Gate Alerts:
- Preclinical only
Methodological Considerations:
- Retrospective design — selection and information bias risk
Abstract: Up to 10% of women may use cannabis during pregnancy; this is of concern because constituents of cannabis cross the placental barrier and potentially influence neurodevelopment by acting on cannabinoid receptors in the developing fetal brain. In this context, a recent meta analysis of 13 observational studies found that gestational exposure to cannabis was associated with a small increase in the risk of autism spectrum disorder (ASD; relative risk [RR], 1.30) and with an even smaller increase in the risk of attention deficit/hyperactivity disorder (ADHD; RR, 1.13); the latter finding was probably supported by publication bias. In this meta-analysis, 4 studies provided information on ASD (pooled N = 178,565) and 10 on ADHD (pooled N = 203,783). In a large (n = 222,534) retrospectively ascertained cohort study published after the meta-analysis, cannabis use disorder (CUD) recorded before pregnancy, during pregnancy, and during pregnancy plus the year after delivery were associated with closely similar increased risks of ASD (RRs, 3.02-3.21). The risks were smaller in smokers (RRs, 1.74-1.87) than in nonsmokers (RRs, 4.55-4.83) but differed little between male (RRs, 3.01-3.06) and female (RRs, 2.71-2.85) offspring. Although the cohort study had many strengths, its limitations permitted only the conclusion that peri-pregnancy exposure to CUD is associated with a large increase in the risk of ASD in offspring; it remained possible that much of the risk was driven by genetic, environmental, or behavioral variables. The field is nascent; the total number of cannabis exposed pregnancies (with ASD and ADHD as the outcomes) in world literature is small. However, cannabis use during pregnancy is, at the very least, a clear marker for adverse neurodevelopmental outcomes, besides the adverse maternal, fetal, and neonatal outcomes identified in other studies. Healthcare providers who manage women who use cannabis during pregnancy need to be aware of these adverse outcomes.
🧠 While this meta-analysis suggests a modest association between prenatal cannabis exposure and increased risk of autism spectrum disorder, clinicians should recognize that observational studies cannot establish causation and are vulnerable to significant confounding by maternal psychiatric conditions, socioeconomic factors, and concurrent substance use that themselves influence neurodevelopmental outcomes. The reported relative risk of 1.30 represents a small absolute increase in population risk, and the heterogeneity among included studies, publication bias favoring positive findings, and residual confounding all warrant cautious interpretation of these findings. Additionally, many women who used cannabis during pregnancy in these cohorts did so before pregnancy recognition, limiting the clinical applicability to intentional use decisions. Rather than categorical prohibition, a practical approach involves screening pregnant patients for cannabis use through compassionate, non-judgmental inquiry; discussing the current evidence regarding potential neurodevelopmental effects; and supporting evidence-based cessation strategies for those willing to discontinue, while recognizing that the harms of stress and untreated maternal psychiatric symptoms must also