Clinical Takeaway
Cannabis use during pregnancy is associated with measurable suppression of maternal immune signaling proteins called cytokines, which play a critical role in protecting both mother and developing fetus. This immune suppression, likely driven by THC acting on cannabinoid receptors in immune cells, raises clinical concern about potential vulnerability to infection and complications during pregnancy. Pregnant patients should be counseled that cannabis is not risk-free and that its effects on maternal immunity represent a legitimate and understudied health concern.
#25 Cannabis Use During Pregnancy Is Associated with the Suppression of Circulating Maternal Cytokines.
Citation: Alshaarawy Omayma et al.. Cannabis Use During Pregnancy Is Associated with the Suppression of Circulating Maternal Cytokines.. Cannabis and cannabinoid research. 2026. PMID: 41104491.
Design: 0 Journal: 1 N: 2 Recency: 3 Pop: 3 Human: 1 Risk: 0
This study addresses a critical knowledge gap regarding how prenatal cannabis use affects maternal immune function at a time when cannabis use in pregnancy is increasing substantially. Suppression of circulating maternal cytokines could have significant implications for pregnancy outcomes and fetal immune development, particularly regarding maternal response to infection and inflammatory regulation. Understanding these immunological effects is essential for informing clinical counseling and evidence-based guidelines on cannabis safety in pregnancy.
Abstract: INTRODUCTION: The prevalence of prenatal cannabis use has nearly doubled in the United States. Cannabinoid 2 receptors are predominately expressed in cells of the human immune system, and delta-9 tetrahydrocannabinol (THC), the primary active component of cannabis, has been shown to suppress immune responses. Despite these findings, there is very little evidence on the impact of cannabis use on maternal immune system. Here, we evaluate the association between urine-verified cannabis use and the levels of T helper cytokines in the maternal circulation. METHODS: This was an ancillary study of a prospective cohort of pregnant women who participated in the Michigan Archive for Research on Child Health study. Pregnant women (age ≥18 years) were recruited from 22 prenatal clinics in Michigan and matched on age, race, and tobacco smoking (n = 144). The urinary metabolite of delta-9 THC, 11-nor-9-carboxy-delta-9-THC (THC-COOH), was used to define cannabis use status. A bead-based assay was used for the simultaneous detection of maternal cytokines associated with cannabis use and pregnancy outcomes in previous studies. RESULTS: Repeated-measures linear mixed models indicated that urine-verified cannabis use was associated with the suppression of maternal pro-inflammatory cytokines including interferon gamma (β = -0.5; 95% confidence interval [CI] = -0.8, -0.1) and interleukin (IL)-12 (β = -0.3; 95% CI = -0.6, -0.05), as well as the anti-inflammatory IL-4 (β = -0.7; 95% CI = -1.3, -0.2) and IL-10 (β = -0.4; 95% CI = -0.7, -0.03). Similar results were observed when heavy cannabis use was defined using the top tertile of urinary THC-COOH at each trimester. CONCLUSIONS: Urine-verified cannabis use was associated with the suppression of pro- and anti-inflammatory T helper cytokines in a cohort of pregnant women, suggesting that cannabis use can lead to modest dysregulation of the maternal immune system. Additional studies are needed to investigate the role of maternal immune resp
🤰 This study identifies an association between verified prenatal cannabis use and suppressed maternal cytokine levels, which raises legitimate concerns about potential immunomodulatory effects during pregnancy when immune tolerance is already physiologically altered. However, several important caveats warrant caution before clinical application: the study does not establish causation, does not measure fetal outcomes, and does not clarify whether cytokine suppression is clinically harmful or merely a biochemical marker without clinical consequence. The timing, frequency, and potency of cannabis use vary considerably among users, and confounders such as concurrent substance use, nutritional status, and infection history were not fully characterized. From a practical standpoint, these findings reinforce the current recommendation to counsel pregnant patients about cannabis use as a potential immunological stressor during a uniquely vulnerable physiological period, while acknowledging that we still lack robust data on actual fetal and neonatal outcomes attributable to this exposure.