Both oral CBD and THC oil during early-to-mid pregnancy in mice impaired blood vessel remodeling, restricted fetal growth, and caused lasting sex-dependent behavioral changes in offspring, challenging the perception that CBD is safe during pregnancy.
Pregnant people considering CBD products; clinicians advising on cannabis during pregnancy; reproductive health researchers
CBD and THC both impaired fetal growth equally
What the researchers found
Oral CBD and THC (20 mg/kg) from early to mid-gestation both impaired maternal spiral artery remodeling and fetal growth. Male offspring showed altered aggression and metabolic activity, while females had impaired spatial learning. Both CBD and THC disrupted immune cell production of angiogenic factors important for placental development.
Why it matters
CBD is increasingly perceived as safe during pregnancy because it is not psychoactive, but this study found oral CBD caused similar fetal harm as THC -- including growth restriction and lasting behavioral changes. This directly challenges the assumption that non-psychoactive means non-harmful.
The numbers in context
CBD and THC doses: 20 mg/kg body weight; both impaired spiral artery remodeling and fetal growth; male offspring: altered aggression and metabolism; female offspring: impaired spatial learning
How the study worked
Mouse model comparing oral CBD oil, THC oil, and controls at 20 mg/kg body weight from early to mid-gestation. Assessed implantation site remodeling, fetal growth, offspring behavior (traditional and automated cage systems), and immune cell angiogenic factor production using human and mouse cells.
What this study cannot tell us
Animal study -- mouse physiology and pregnancy differ from humans. Single high dose tested (20 mg/kg). Only early-to-mid gestation exposure examined. Did not test lower "consumer-relevant" doses. Route (oral oil) may not reflect all human consumption methods.
How to read the evidence
Well-designed animal study with multiple outcome measures, but findings in mice do not directly translate to human pregnancy.
When this study was published
Published in 2025.
The bigger picture
With CBD product use rising during pregnancy (often for nausea or anxiety), this study adds critical preclinical evidence that oral CBD may not be the safe alternative many assume. The sex-dependent offspring effects add another layer of complexity.
Questions still open
- Do lower CBD doses during pregnancy also impair fetal development? Are the offspring behavioral changes permanent or do they resolve with maturity? What is the mechanism by which CBD disrupts spiral artery remodeling?
Common questions
Is CBD safe during pregnancy?
Were the effects on offspring permanent?
Read the original research
The impact of oral cannabis consumption during pregnancy on maternal spiral artery remodelling, fetal growth and offspring behaviour in mice.
EBioMedicine, 114, 105572
Citation
Ritchie, Tyrah M; Feng, Emily; Vahedi, Fatemeh; Ermolina, Sofya; Bellissimo, Christian J; De Jong, Erica; Portillo, Ana L; Poznanski, Sophie M; Chan, Lauren; Ettehadieh, Sara M; Sloboda, Deborah M; Bowdish, Dawn M E; Ashkar, Ali A. (2025). The impact of oral cannabis consumption during pregnancy on maternal spiral artery remodelling, fetal growth and offspring behaviour in mice.. EBioMedicine, 114, 105572. https://doi.org/10.1016/j.ebiom.2025.105572
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