Prenatal cannabis use disorder was linked to a rare abdominal wall birth defect in a California study of 5.8 million births | Research

The takeaway

In a California population study of nearly 5.8 million births, prenatal cannabis use disorder was associated with a 30-50% increased risk of gastroschisis, with the strongest association in mothers over 34.

OB-GYN providers counseling pregnant patients about cannabis use; epidemiologists studying birth defect trends.

5.8 million births; 30-50% higher gastroschisis risk with prenatal CUD

What the researchers found

Cannabis use disorder during pregnancy was associated with gastroschisis (a birth defect where intestines protrude through the abdominal wall). The multivariable model showed an adjusted risk ratio of 1.3 (95% CI 1.0-1.7), and a matched sample approach showed aRR 1.5 (95% CI 1.1-2.1). The association was strongest in mothers over 34 (aRR 2.5, 95% CI 1.0-5.8).

Why it matters

Gastroschisis rates have been rising for unknown reasons, and cannabis use has increased during the same period. This large population study suggests a possible connection worth further investigation, particularly for older mothers.

The numbers in context

5,774,656 births analyzed. Cannabis use disorder prevalence was about 1%. Gastroschisis prevalence: 0.14% in CUD-exposed vs 0.06% in unexposed. Adjusted risk ratio 1.3-1.5 depending on method. Mothers over 34: aRR 2.5.

How the study worked

Population-based cohort using California birth records linked to hospital, ED, and ambulatory surgery records from 2007-2019. 5,774,656 singleton live births analyzed. Cannabis use disorder measured by diagnosis codes during pregnancy or at birth.

What this study cannot tell us

Cannabis use disorder diagnosis codes likely undercount actual cannabis use. Cannot determine dose, timing, or frequency of use. Observational design cannot establish causation. Residual confounding from other substance use or socioeconomic factors is possible.

How to read the evidence

Large population-based cohort with linked medical records, though reliance on diagnosis codes may undercount exposure.

When this study was published

2024 study

The bigger picture

If confirmed as causal, this association could partly explain rising gastroschisis rates as cannabis use has become more common. The age-dependent pattern raises questions about how maternal age interacts with cannabinoid exposure during fetal development.

Questions still open

What biological mechanism could link cannabis to abdominal wall defects? Why is the association strongest in older mothers?

Common questions

What is gastroschisis?

A birth defect where the baby's intestines (and sometimes other organs) extend outside the body through a hole in the abdominal wall, usually to the right of the belly button. It requires surgical repair after birth.

Does this prove cannabis causes gastroschisis?

No. This is an observational study showing an association. The researchers note that more investigation is needed to determine whether the relationship is causal.

Read the original research

Prenatal cannabis use disorder and gastroschisis in California, 2007-19.

International journal of epidemiology, 53(2)

View on PubMed ↗Publisher’s paper ↗

Citation

Delker, Erin; Baer, Rebecca J; Kelly, Ann E; Chambers, Christina; Bandoli, Gretchen. (2024). Prenatal cannabis use disorder and gastroschisis in California, 2007-19.. International journal of epidemiology, 53(2). https://doi.org/10.1093/ije/dyae042