The rate of prenatal marijuana use in the United States has more than doubled over the past two decades, with many pregnant individuals turning to marijuana to manage symptoms like nausea, anxiety, and insomnia. While marijuana use during pregnancy is increasing, so is the clarity of the science surrounding its risks. A growing body of research makes it clear that marijuana use during pregnancy is not without consequences.

A new meta-analysis of over 51 studies, covering over 21 million pregnancies, now offers one of the most comprehensive assessments to date.

The findings are clear: marijuana use during pregnancy is linked to measurable risks for both the mom and the baby, even after accounting for other factors like tobacco use. Researchers found that prenatal marijuana use increased the odds of several serious outcomes. Researchers found that prenatal marijuana use was associated with:

  • 75% higher odds of a child being born with low birth weight,
  • 52% higher odds of preterm birth,
  • 57% higher odds of the fetus being small for gestational age, and
  • 29% rise in perinatal mortality, however, the strength of this association was less certain.

In studies that accounted for variables that could influence the relationship between marijuana use and the different outcomes, such as age, smoking and health status, the association remained significant. And in the studies that accounted for a dose-response association, the risks grew even more pronounced. For example, babies exposed to heavy marijuana use were more than twice as likely to be born with low birth weight, had 95% and 63% higher odds being born preterm and small for gestational age, respectively.

Being born with low birth weight, preterm, or small for gestational age is not just a number on a chart—it carries real and lasting health consequences. These findings underscore the urgency of addressing marijuana use during pregnancy as a serious public health issue. As marijuana products become more potent and widely available, the risks to developing fetuses cannot be overlooked.

For providers, it is important to have nonjudgmental conversations about the risks associated with marijuana use during pregnancy and for public health leaders, it’s a call to expand prevention efforts.

Explore science-based resources on marijuana, pregnancy, and parenting at: marijuanaknowthetruth.org/marijuana-and-pregnancy. Engage with the latest research, reflect on the implications, and initiate meaningful conversations within your community.

To deepen your understanding of marijuana and its broader implications, enroll in our FREE online course using code DFAF_FL-MJ23 to gain complimentary access and enhance your knowledge. This course covers:

  • The history and evolution of marijuana potency and products
  • Marketing tactics and public safety considerations
  • Effects of marijuana on mental and physical health
  • Specific risks during pregnancy and breastfeeding

Source:

Rosenberg, A. R., Orellana, L., Ullrich, C., Kang, T., Geyer, J. R., Feudtner, C., Dussel, V., & Wolfe, J. (2016). Quality of Life in Children With Advanced Cancer: A Report From the PediQUEST Study. Journal of pain and symptom management, 52(2), 243–253. https://doi.org/10.1016/j.jpainsymman.2016.04.002

Lo JO, Ayers CK, Yeddala S, et al. Prenatal Cannabis Use and Neonatal Outcomes: A Systematic Review and Meta-Analysis. JAMA Pediatr. (2025). doi:10.1001/jamapediatrics.2025.0689

Cupo, L., Dominguez-Cancino, K. A., Nazif-Munoz, J. I., & Chakravarty, M. M. (2024). Prenatal cannabis exposure in the clinic and laboratory: What do we know and where do we need to go?. Drug and alcohol dependence reports, 13, 100282. https://doi.org/10.1016/j.dadr.2024.100282

Columbia University Mailman School of Public Health. (2025). Cannabis use disorder diagnoses rise among pregnant women as legalization expands. Columbia University Mailman School of Public Health. from https://www.publichealth.columbia.edu/news/cannabis-use-disorder-diagnoses-rise-among-pregnant-women-legalization-expands

Escañuela Sánchez, T., Matvienko-Sikar, K., Linehan, L., O’Donoghue, K., Byrne, M., & Meaney, S. (2022). Facilitators and barriers to substance-free pregnancies in high-income countries: A meta-synthesis of qualitative research. Women and Birth, 35(2), e99-e110. https://doi.org/10.1016/j.wombi.2021.04.010