Rhesus macaque infants exposed to daily edible THC during gestation showed reduced lung volumes and altered gene expression at 6 months of age.
prenatal health researchers, obstetricians, pulmonologists, cannabis policy researchers
What the researchers found
THC-exposed infant macaques had significantly reduced forced residual capacity, along with decreased total lung capacity, lung diffusion capacity, and lower fetal lung perfusion on prenatal MRI. Molecular analysis revealed altered DNA methylation at genes involved in extracellular matrix organization and lung development.
Why it matters
Prenatal cannabis use is rising alongside legalization and perceptions of safety, but the respiratory effects on offspring have been largely unknown. This primate model provides more translatable data than rodent studies.
The numbers in context
THC dose was 2.5 mg/7 kg/day (equivalent to heavy medical cannabis use). Significant reduction in forced residual capacity at 6 months. Decreased pulmonary growth factors in bronchial alveolar lavage. Altered epigenetic regulation at genes for extracellular matrix organization, lung development, and immune signaling.
How the study worked
Female rhesus macaques received daily edible THC (2.5 mg/7 kg/day, equivalent to a heavy medical cannabis dose) or placebo during gestation and postnatally. Serial MRI was performed during pregnancy. At 6 months, infants underwent pulmonary function testing and tissue collection for bulk RNAseq, whole genome bisulfite sequencing, and spatial RNAseq.
What this study cannot tell us
Small sample size typical of primate studies. THC was given as a single compound rather than whole-plant cannabis. The dose represents heavy use and may not reflect typical consumption. Follow-up only to 6 months of age. No behavioral or long-term respiratory outcomes.
How to read the evidence
Well-designed primate model with molecular validation, but small sample sizes and the inherent limitations of animal-to-human translation keep this at preliminary.
When this study was published
Recently published primate research.
The bigger picture
This is one of the first primate studies examining respiratory outcomes of prenatal THC exposure. The epigenetic changes suggest the effects may be programmed early in development, though it remains unclear whether these changes persist into adulthood or cause clinical disease.
Questions still open
- Do the lung function deficits persist or worsen with age?
- Would lower THC doses produce similar effects?
Common questions
Does this mean cannabis during pregnancy harms fetal lungs?
What kind of THC was used?
Read the original research
Effects of maternal edible THC consumption on offspring lung growth and function in a rhesus macaque model.
American journal of physiology. Lung cellular and molecular physiology, 328(3), L463-L477
Citation
Shorey-Kendrick, Lyndsey E; Crosland, B Adam; Schabel, Matthias C; Messaoudi, Ilhem; Guo, Minzhe; Drake, Matthew G; Nie, Zhenying; Edenfield, R Clayton; Cinco, Issac; Davies, Michael H; Graham, Jason A; Hagen, Olivia L; McCarty, Owen J T; McEvoy, Cindy T; Spindel, Eliot R; Lo, Jamie O. (2025). Effects of maternal edible THC consumption on offspring lung growth and function in a rhesus macaque model.. American journal of physiology. Lung cellular and molecular physiology, 328(3), L463-L477. https://doi.org/10.1152/ajplung.00360.2024
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