Systematic review finds mixed evidence on whether cannabis in pregnancy causes birth defects
A systematic review of 20 studies found mixed results for associations between prenatal cannabis exposure and structural birth defects, with too little research on most organ systems to draw conclusions.
Quick Facts
What This Study Found
For the most-studied defect types (cardiac, gastrointestinal, CNS), findings were mixed across studies. For less-studied defect types (orofacial, eye, genitourinary, musculoskeletal), the sparse research mostly found no association, but sample sizes were too small for confidence.
Key Numbers
20 articles identified, 12 with adjusted analyses included in interpretation. Seven organ systems examined: cardiac (4 studies), CNS (3), gastrointestinal (3), orofacial (2), eye (1), genitourinary (1), musculoskeletal (1).
How They Did This
Systematic review following PRISMA guidelines. Identified 20 articles, with analysis focused on 12 that adjusted for potential confounders. Findings organized by seven organ systems.
Why This Research Matters
Cannabis use during pregnancy is increasing, and pregnant people need clear information about risks. The current evidence on birth defects is too sparse and inconsistent to provide definitive guidance.
The Bigger Picture
Most research on cannabis in pregnancy has focused on low birth weight and preterm birth. Structural birth defects have received far less attention, leaving a significant gap in reproductive safety data.
What This Study Doesn't Tell Us
Few studies per organ system make conclusions unreliable. Heterogeneous exposure definitions across studies. Most studies rely on self-reported cannabis use. Confounding by tobacco, alcohol, and other substance co-use is difficult to fully address.
Questions This Raises
- ?Would studies using biomarker-verified cannabis exposure produce different results?
- ?Are there critical windows during organogenesis when cannabis exposure poses the greatest risk?
Trust & Context
- Key Stat:
- Only 12 of 20 studies adjusted for confounders; findings mixed across organ systems
- Evidence Grade:
- Systematic review with rigorous methodology, but limited by the sparse and inconsistent underlying evidence base.
- Study Age:
- Published 2023.
- Original Title:
- A systematic review of in utero cannabis exposure and risk for structural birth defects.
- Published In:
- Frontiers in pediatrics, 11, 1149401 (2023)
- Authors:
- Sujan, Ayesha C(2), Pal, Anish, Avalos, Lyndsay A(13), Young-Wolff, Kelly C
- Database ID:
- RTHC-04965
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
Does cannabis cause birth defects?
The evidence is insufficient to answer definitively. This systematic review found mixed results for the most-studied defect types (heart, brain, gastrointestinal) and too little research on others. The absence of a clear association does not mean cannabis is safe during pregnancy.
Why is the evidence so limited?
Studying birth defects requires very large samples because individual defect types are rare. Most cannabis-pregnancy studies have focused on more common outcomes like birth weight. Additionally, accurately measuring cannabis exposure during pregnancy is difficult.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-04965APA
Sujan, Ayesha C; Pal, Anish; Avalos, Lyndsay A; Young-Wolff, Kelly C. (2023). A systematic review of in utero cannabis exposure and risk for structural birth defects.. Frontiers in pediatrics, 11, 1149401. https://doi.org/10.3389/fped.2023.1149401
MLA
Sujan, Ayesha C, et al. "A systematic review of in utero cannabis exposure and risk for structural birth defects.." Frontiers in pediatrics, 2023. https://doi.org/10.3389/fped.2023.1149401
RethinkTHC
RethinkTHC Research Database. "A systematic review of in utero cannabis exposure and risk f..." RTHC-04965. Retrieved from https://rethinkthc.com/research/sujan-2023-a-systematic-review-of
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.