Urine-verified cannabis use during pregnancy was associated with suppression of both pro-inflammatory and anti-inflammatory cytokines, suggesting modest immune dysregulation that could affect birth outcomes.
Pregnant individuals considering cannabis use, OB-GYNs, immunologists, and maternal health researchers
What the researchers found
Cannabis use suppressed pro-inflammatory cytokines IFN-γ (β=-0.5) and IL-12 (β=-0.3) and anti-inflammatory cytokines IL-4 (β=-0.7) and IL-10 (β=-0.4) in pregnant women, indicating broad immune modulation rather than simple immunosuppression.
Why it matters
Pregnancy requires precise immune balance to protect both mother and baby — cannabis disrupting both pro- and anti-inflammatory signals could explain some of the adverse birth outcomes linked to prenatal use.
The numbers in context
144 matched participants; IFN-γ β=-0.5 (95% CI -0.8 to -0.1); IL-12 β=-0.3 (-0.6 to -0.05); IL-4 β=-0.7 (-1.3 to -0.2); IL-10 β=-0.4 (-0.7 to -0.03).
How the study worked
Ancillary prospective cohort study of 144 pregnant women from the MARCH cohort matched on age, race, and tobacco smoking, using urine-verified THC-COOH to define cannabis use and bead-based multiplex cytokine assays with repeated-measures linear mixed models.
What this study cannot tell us
Modest sample size (n=144); observational design cannot establish causation; cytokine levels are systemic and may not reflect placental immune environment.
How to read the evidence
Well-matched prospective cohort with urine verification and repeated measures, but limited sample size and observational design prevent causal conclusions.
When this study was published
Published in 2026 from the NIH ECHO-affiliated MARCH cohort, using objective biomarker verification.
The bigger picture
This provides a potential biological mechanism for why cannabis use during pregnancy is linked to adverse outcomes — immune dysregulation during a period when precise immune balance is critical for fetal development.
Questions still open
- Do these immune changes persist after cannabis cessation during pregnancy? Is the cytokine suppression dose-dependent? Could immune dysregulation explain specific adverse birth outcomes?
Common questions
Does cannabis use during pregnancy affect the immune system?
Why does maternal immune suppression matter during pregnancy?
Read the original research
Cannabis Use During Pregnancy Is Associated with the Suppression of Circulating Maternal Cytokines.
Cannabis and cannabinoid research, 11(1), 78-88
Citation
Alshaarawy, Omayma; Sotzen, Morgan; Kurjan, Emily; Padmanabhan, Vasantha; Ruden, Douglas M; Olson, L Karl. (2026). Cannabis Use During Pregnancy Is Associated with the Suppression of Circulating Maternal Cytokines.. Cannabis and cannabinoid research, 11(1), 78-88. https://doi.org/10.1177/25785125251388764
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