Fetal Exposure to Marijuana Linked to Increased Fat Mass, Glucose Levels in Early Life

Brianna Moore, PhD

Data from a study of 103 mother-child pairs from Colorado provides evidence detailing an association between fetal exposure to cannabis with increased fat mass and increased fasting glucose in early life.

A 5-year follow-up of children born to mothers included in the 2016 Healthy Start study, results demonstrate children with fetal exposure to cannabis had increased adiposity and greater fasting glucose levels than their counterparts without fetal exposure to cannabis, which included CBD, THC, and 10 other different cannabinoids/metabolites.

“We found that cannabis use during pregnancy was linked to increased fat mass percentage and fasting glucose levels in 5-year-old children,” said Brianna Moore, PhD, of the Colorado School of Public Health, in a statement. “We would encourage women to refrain from using any cannabis while pregnant or breastfeeding to minimize adverse health effects in the offspring.”

Launched in 2009, the Healthy Start study was designed with the intent of assessing the impact of metabolic and behavioral factors during pregnancy on development of obesity, insulin resistance, and inflammatory markers in newborns and infants. With pregnant women recruited from outpatient obstetrics clinics at the University of Colorado Hospital, the study enrolled 1410 mothers from 2010-2014, with all women enrolled before 24 weeks gestation.

In the current study, investigators sought to examine the effects of fetal exposure to cannabis among a subsample of 199 women with stored urine samples collected from a convenience sample at 27 weeks’ gestation. Samples from these women were analyzed using an Agilent 1200 HPLC system and AB SCIEX API5000 tandem mass spectrometer for measurements of THC, 11-hydroxy-THC, THCCOOH, THC-9-carboxylic acid glucuronide (THC-C-gluc), THC glucuronide (THC-gluc), cannabidiol (CBD), CBD glucuronide, cannabichromene (CBC), cannabinol (CBN), cannabigerol (CBG), Δ9-tetrahydrocannabivarin (THCV), and cannabidivarin (CBDV).

For the purpose of analysis, fetal exposure to cannabis was categorized as exposed and not exposed, with exposure defined as any cannabinoid or its metabolite exceeding the limit detection. Investigators used generalized linear models to estimate associations between fetal exposure to cannabis with fat mass, fat-free mass, fat mass percentage, BMI, BMI z-scores, glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR).

Investigators noted missing data resulted in the adiposity analysis containing 103 participants and the metabolic outcomes analysis containing 88 participants. Initial analysis of urine samples indicated approximately 15% of mothers had detectable levels of any cannabinoid at 27 weeks’ gestation. Compared to those with no fetal exposure to cannabis, offspring with fetal exposure were more likely to be female (P=.02), born at a lower birth weight (P <.01), and been concurrently exposed to tobacco in utero (P <.01), as well as during early childhood (P=.03).

Results of the investigators analyses suggested exposed offspring had higher fat mass (1.0 kg; 95% CI, 0.3-1.7), fat-free mass (1.2 kg; 95% CI, 0.4-2.0), adiposity (2.6%; 95% CI, 0.1-5.2), and fasting glucose (5.6 mg/dL; 95% CI, 0.8-10.3) than those without fetal exposure to cannabis. Investigators pointed out no associations were observed for fasting insulin, HOMA-IR, BMI, or BMI z-scores.

Investigators cautioned that clinicians should consider the limitations of their study before interpreting results and pointed out further research is needed on the subject to validate the findings of their investigation.

“More studies are needed to understand how exposure to different cannabinoids during pregnancy may impact the offspring,” Moore said.

This study, “Fetal Exposure to Cannabis and Childhood Metabolic Outcomes: The Healthy Start Study,” was published in The Journal of Clinical Endocrinology and Metabolism.