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Study breakdown

Review of maternal and newborn adverse outcomes from cannabis use during pregnancy

Narrative ReviewModerate evidence
The takeaway

Cannabis use during pregnancy is associated with increased risks of preterm birth, low birth weight, NICU admission, fetal death, gestational hypertension, and placental abruption, with greater risk at higher use frequency.

Pregnant individuals using or considering cannabis, obstetricians, maternal health advocates

Risk increases with use frequency

What the researchers found

Maternal cannabis use during pregnancy was associated with small to moderately increased risks of gestational hypertension, abnormal gestational weight gain, placental abruption, preterm birth (<36, <34, and <32 weeks), small for gestational age, low birth weight, NICU admission, and fetal death, even in women not using other substances.

Why it matters

Over 5% of women use cannabis during pregnancy, often for nausea, anxiety, or pain, and many are unaware of pregnancy-related risks. Cannabis constituents cross the placenta and act on receptors in the developing fetal brain.

The numbers in context

Over 5% of women use cannabis during pregnancy. Increased risks identified for preterm birth at <36, <34, and <32 weeks. Risks were greater with greater frequency of use. Adverse outcomes persisted even when excluding women using other substances.

How the study worked

Narrative review of recent cohort studies and meta-analyses examining specific maternal and neonatal adverse outcomes associated with gestational cannabis exposure.

What this study cannot tell us

Observational data cannot prove causation. Women who use cannabis may differ from non-users in ways that independently affect pregnancy outcomes. Self-report likely underestimates use. Some studies could not separate cannabis from tobacco effects.

How to read the evidence

Narrative review of multiple cohort studies and meta-analyses, providing consistent but observational evidence across outcomes.

When this study was published

2024 review of recent pregnancy outcome studies

The bigger picture

As cannabis legalization expands and public risk perception decreases, the gap between availability and understanding of pregnancy risks widens. Multiple professional bodies worldwide already discourage cannabis use during pregnancy based on this accumulating evidence.

Questions still open

  • Is there a safe level of cannabis use during pregnancy? How do different consumption methods (smoking vs. edibles) compare in pregnancy risk?

Common questions

What pregnancy complications are linked to cannabis?
The review identified associations with gestational hypertension, placental abruption, preterm birth, low birth weight, small for gestational age, NICU admission, and fetal death.
Do these risks apply to women who only use cannabis and no other substances?
Yes. Several studies found adverse outcomes specifically in women who did not use other substances during pregnancy, though confounding from other factors cannot be fully eliminated.

Read the original research

Maternal Cannabis Use During Pregnancy and Maternal and Neonatal Adverse Outcomes.

The Journal of clinical psychiatry, 85(4)

Citation

Andrade, Chittaranjan. (2024). Maternal Cannabis Use During Pregnancy and Maternal and Neonatal Adverse Outcomes.. The Journal of clinical psychiatry, 85(4). https://doi.org/10.4088/JCP.24f15611

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