Children exposed to cannabis in the womb had higher BMI and body fat at age 10, but shared family factors may explain the link

Children exposed to maternal cannabis during pregnancy had higher BMI and altered body fat distribution at age 10, but similar patterns for paternal cannabis use suggest shared family lifestyle factors rather than direct fetal programming.

Cajachagua-Torres, Kim N et al.·Pediatric obesity·2022·Moderate EvidenceProspective Cohort
RTHC-03738Prospective CohortModerate Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Prospective Cohort
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Children exposed to maternal cannabis during pregnancy had higher BMI (0.26 SDS), android/gynoid fat ratio (0.21 SDS), and fat-free mass index (0.24 SDS) at age 10. However, paternal substance use showed similar associations with child cardiometabolic outcomes, suggesting shared family-based social and lifestyle factors rather than direct intrauterine effects.

Key Numbers

4,792 families. Maternal cannabis exposure: +0.26 SDS BMI, +0.21 SDS android/gynoid fat ratio, +0.24 SDS fat-free mass index. Paternal associations were similar in magnitude.

How They Did This

Population-based prospective cohort of 4,792 mothers, fathers, and children. Parental substance use assessed by questionnaires during pregnancy. Child outcomes measured at age 10: BMI, body fat (DXA), blood pressure, lipids, glucose, and insulin.

Why This Research Matters

By comparing maternal and paternal exposure associations, this study provides an important reality check: what looks like a direct effect of prenatal cannabis exposure may actually reflect the environment children grow up in.

The Bigger Picture

This study illustrates a critical methodological point in prenatal exposure research: when paternal exposures (which cannot directly affect the fetus) produce similar associations as maternal exposures, confounding by shared family factors is the most likely explanation.

What This Study Doesn't Tell Us

Self-reported substance use. Paternal data used as negative control but may have direct biological effects (epigenetic). Cannot fully rule out direct fetal effects of cannabis. Loss to follow-up over 10 years.

Questions This Raises

  • ?Are the observed differences clinically meaningful?
  • ?Could epigenetic paternal effects also contribute?
  • ?Would controlling for diet, exercise, and socioeconomic factors fully explain the associations?

Trust & Context

Key Stat:
Similar effects for maternal and paternal use suggest family factors, not fetal programming
Evidence Grade:
Large prospective cohort with objective childhood measurements, strengthened by paternal exposure comparison.
Study Age:
Published in 2022 with outcome measurements at age 10.
Original Title:
Foetal tobacco and cannabis exposure, body fat and cardio-metabolic health in childhood.
Published In:
Pediatric obesity, 17(3), e12863 (2022)
Database ID:
RTHC-03738

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Enrolls participants and follows them forward in time.

What do these levels mean? →

Frequently Asked Questions

Does cannabis during pregnancy cause childhood obesity?

Children exposed to maternal cannabis had higher BMI and body fat at age 10. However, paternal cannabis use showed similar associations, suggesting the link is more likely due to shared family lifestyle factors than direct effects on the developing fetus.

Why does paternal cannabis use matter for this research?

Paternal substance use serves as a negative control: since fathers' cannabis use cannot directly affect the fetus through the placenta, finding similar associations for both parents suggests that shared family environment and lifestyle, not direct fetal exposure, drives the observed outcomes.

Read More on RethinkTHC

Cite This Study

RTHC-03738·https://rethinkthc.com/research/RTHC-03738

APA

Cajachagua-Torres, Kim N; El Marroun, Hanan; Reiss, Irwin K M; Santos, Susana; Jaddoe, Vincent W V. (2022). Foetal tobacco and cannabis exposure, body fat and cardio-metabolic health in childhood.. Pediatric obesity, 17(3), e12863. https://doi.org/10.1111/ijpo.12863

MLA

Cajachagua-Torres, Kim N, et al. "Foetal tobacco and cannabis exposure, body fat and cardio-metabolic health in childhood.." Pediatric obesity, 2022. https://doi.org/10.1111/ijpo.12863

RethinkTHC

RethinkTHC Research Database. "Foetal tobacco and cannabis exposure, body fat and cardio-me..." RTHC-03738. Retrieved from https://rethinkthc.com/research/cajachagua-torres-2022-foetal-tobacco-and-cannabis

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.