Is prenatal cannabis exposure associated with behavioral and cognitive differences in children? | Research

The takeaway

In the largest study of its kind, data from 11,489 children ages 9-11 found that prenatal cannabis exposure was associated with greater psychopathology, sleep problems, higher BMI, and lower cognitive scores, even after controlling for extensive familial and environmental factors.

Pregnant individuals considering cannabis use, clinicians counseling pregnant patients, and researchers studying developmental effects of prenatal substance exposure.

11,489 children; 5.7% prenatally exposed

What the researchers found

Children exposed to cannabis prenatally showed greater psychotic-like experiences, internalizing, externalizing, attention, thought, and social problems, more sleep difficulties, higher BMI, and lower cognitive performance. After adjusting for familial, pregnancy, and child covariates, many associations attenuated but prenatal exposure before maternal knowledge of pregnancy remained associated with psychopathology and cognition.

Why it matters

With cannabis use among pregnant women increasing, this large study from a premier national cohort provides the most comprehensive picture yet of associations between prenatal exposure and childhood outcomes. Published in JAMA Psychiatry, it informed the US Surgeon General advisory against cannabis use during pregnancy.

The numbers in context

11,489 children; 655 (5.7%) prenatally exposed; 413 exposed before and 242 after maternal knowledge of pregnancy; associations with psychopathology, sleep, BMI, cognition, and reduced gray matter volume

How the study worked

Cross-sectional analysis of the Adolescent Brain and Cognitive Development (ABCD) Study baseline, including 11,489 children aged 9-11 from 22 US sites. 655 (5.7%) were prenatally exposed to cannabis. Extensive covariates included family income, familial psychopathology, prenatal alcohol and tobacco, and child substance use.

What this study cannot tell us

Cross-sectional baseline data; causal inference limited. Maternal self-report of prenatal cannabis use may be subject to recall bias. Cannot separate cannabis effects from correlated lifestyle factors despite extensive controls.

How to read the evidence

Large national cohort from JAMA Psychiatry with extensive covariates, though cross-sectional design limits causal claims.

When this study was published

Published in 2021; longitudinal ABCD follow-up data will strengthen these findings.

The bigger picture

While this study cannot prove causation due to its cross-sectional design, the breadth of associated outcomes and the large, diverse sample strengthen the case for caution. The finding that even exposure limited to before pregnancy awareness was associated with differences suggests early gestational vulnerability.

Questions still open

Will longitudinal ABCD data show whether these associations persist or change over adolescence? Can effects of prenatal cannabis be separated from prenatal tobacco and alcohol? Is there a critical window during gestation when exposure is most consequential?

Common questions

Does cannabis during pregnancy harm the baby?

This large study found associations between prenatal cannabis exposure and a range of childhood outcomes including behavioral problems, lower cognition, and sleep difficulties. However, the design cannot prove cannabis caused these effects versus other correlated factors.

Does it matter when during pregnancy cannabis was used?

Exposure both before and after the mother learned of the pregnancy was associated with adverse outcomes, suggesting early gestational periods may be vulnerable. Continued exposure after pregnancy awareness was associated with additional effects on attention and birth weight.

How common is prenatal cannabis exposure?

In this nationally representative sample of children born around 2007-2009, 5.7% were exposed to cannabis prenatally. Rates of use during pregnancy have increased since then.

Read the original research

Associations Between Prenatal Cannabis Exposure and Childhood Outcomes: Results From the ABCD Study.

JAMA psychiatry, 78(1), 64-76

View on PubMed ↗Publisher’s paper ↗

Citation

Paul, Sarah E; Hatoum, Alexander S; Fine, Jeremy D; Johnson, Emma C; Hansen, Isabella; Karcher, Nicole R; Moreau, Allison L; Bondy, Erin; Qu, Yueyue; Carter, Ebony B; Rogers, Cynthia E; Agrawal, Arpana; Barch, Deanna M; Bogdan, Ryan. (2021). Associations Between Prenatal Cannabis Exposure and Childhood Outcomes: Results From the ABCD Study.. JAMA psychiatry, 78(1), 64-76. https://doi.org/10.1001/jamapsychiatry.2020.2902