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What We Know About Cannabis Use During Pregnancy and Breastfeeding

ReviewModerate evidence
The takeaway

This comprehensive review covers cannabis pharmacology, evidence on perinatal outcomes, and harm reduction strategies, noting that nearly half of active cannabis users continue use during pregnancy.

Pregnant individuals considering cannabis use, OB-GYNs, midwives, pediatricians, and lactation consultants.

What the researchers found

Cannabis use in pregnancy has a prevalence of 3-30%, with nearly half of active users continuing despite medical guidance against it. The review summarizes current evidence on THC exposure impacts on pregnancy, infant, and childhood outcomes.

Why it matters

With cannabis legalization expanding, more pregnant people are using cannabis. Healthcare providers need clear, evidence-based guidance to counsel patients about risks without being dismissive of their choices.

The numbers in context

Cannabis use prevalence during pregnancy: 3-30%. Nearly 50% of active cannabis users continue use during pregnancy. Major medical organizations (ACOG, AAP) discourage use.

How the study worked

Narrative review summarizing cannabis pharmacology and THC metabolism, current evidence on perinatal cannabis effects, and targeted counseling recommendations for harm reduction during pregnancy and lactation.

What this study cannot tell us

Evidence on perinatal cannabis effects has significant confounders (polysubstance use, socioeconomic factors). Self-report underestimates true use. Long-term childhood outcome data is limited.

How to read the evidence

Narrative review synthesizing heterogeneous evidence — provides practical clinical guidance but acknowledges significant limitations in the underlying data.

When this study was published

Recent review reflecting current understanding and the practical challenges of counseling in an era of expanding cannabis legalization.

The bigger picture

The gap between medical recommendations and patient behavior around prenatal cannabis use demands practical harm reduction approaches rather than abstinence-only messaging that patients are clearly not following.

Questions still open

  • What are the safest harm reduction strategies for pregnant cannabis users who won't quit? How does THC potency in modern products change the risk calculus compared to older studies?

Common questions

Is cannabis safe during pregnancy?
Major medical organizations recommend against it due to potential risks to fetal development. However, evidence is complicated by confounders, and the review focuses on practical harm reduction for those who continue use.
Does THC pass through breast milk?
Yes — THC is lipophilic and accumulates in breast milk. The review discusses lactation considerations, though data on infant outcomes from breastmilk THC exposure remains limited.

Read the original research

High Stakes: Exploring the Impact of Cannabis Use in Pregnancy and Lactation.

NeoReviews, 26(4), e247-e263

Citation

Wymore, Erica M; Wagner, Katharine; Gold, Christine; Halmo, Laurie Seidel. (2025). High Stakes: Exploring the Impact of Cannabis Use in Pregnancy and Lactation.. NeoReviews, 26(4), e247-e263. https://doi.org/10.1542/neo.26-4-006

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