Fetal exposure to cannabis and childhood behavior at age 5 years: The Healthy Start study

Objective: To assess whether fetal exposure to cannabis is associated with childhood behavior, independent of fetal exposure to nicotine. Study design: This pilot study included 97 mother-child pairs from a Colorado-based cohort. Maternal urine was collected at ~27 weeks gestation and analyzed for cotinine and twelve cannabinoids/metabolites (including delta 9-tetrahydrocannabinol and cannabidiol). Fetal exposure to cannabis was dichotomized as exposed (any cannabinoid≥limit of detection [LOD]) and not exposed. Fetal exposure to nicotine was dichotomized as exposed (cotinine≥LOD) and not exposed. Generalized linear models examined the associations of fetal exposure to cannabis with Child Behavior Checklist T-scores at age 5 years, with and without adjustment for fetal exposure to nicotine. Results: Compared to non-exposed offspring, cannabis-exposed offspring exhibited more externalizing behaviors (β: 4.3; 95% CI: 0.2, 8.5; p=0.04). However, this association was attenuated after adjusting for fetal exposure to nicotine (β: 2.1; 95% CI: -2.5, 6.6; p=0.38). Fetal exposure to nicotine was associated with several behavioral outcomes, including externalizing behaviors (β: 10.2; 95% CI: 2.9, 17.5; p<0.01), sleep problems (β: 4.5; 95% CI: 2.5, 7.6; p<0.01), and attention problems (β: 4.8; 95% CI: 1.7, 8.0; p<0.01), independent of cannabis exposure. Conclusions: Our study confirms that fetal exposure to nicotine is associated with childhood behavioral outcomes, but more studies are needed to understand the long-term impact of fetal exposure to cannabis. Nevertheless, the potential risks of nicotine and cannabis use during pregnancy should be more widely communicated to limit behavioral problems in the offspring.