Among 197 mother-child pairs, prenatal insecticide exposure (not cannabis itself) was associated with altered child behavior, but cannabis exposure modified the effects of the insecticide-tobacco mixture in sex-specific ways.
Prenatal health researchers, toxicologists, and clinicians counseling pregnant patients about environmental exposures.
What the researchers found
Prenatal insecticides (pyrethroids and organophosphates) were the primary exposures associated with child neurobehavior. Pyrethroid exposure (3PBA) was positively associated with internalizing behaviors (beta=18.1%). Cannabis (THCCOOH) modified the cumulative effect of the tobacco-insecticide mixture: among females with detectable cannabis exposure, the mixture was associated with lower externalizing behaviors (beta=-46.8%, 95% CI: -70.4%, -4.1%).
Why it matters
Cannabis and tobacco crops are commonly contaminated with insecticides. This study is one of the first to examine how these co-exposures interact during pregnancy, revealing that cannabis may modify the neurodevelopmental effects of pesticides in sex-specific ways.
The numbers in context
197 mother-child pairs. Pyrethroid (3PBA) and internalizing: beta=18.1% (95% CI: 0.0%, 39.5%). TCPY and externalizing: beta=-12.9% (95% CI: -27.8%, 5.0%). Females with detectable THCCOOH, mixture and externalizing: beta=-46.8% (95% CI: -70.4%, -4.1%). Effects were modified by both THCCOOH and sex.
How the study worked
Prospective cohort of 197 mother-child pairs from Atlanta, Georgia. Cannabis, tobacco, pyrethroid, and organophosphate metabolites measured in maternal urine at 8-14 and 24-30 weeks' gestation. Infant arousal and attention assessed at 2 weeks; child behavior assessed annually at ages 2-5 using CBCL. Quantile g-computation and Bayesian kernel machine regression analyzed mixture effects.
What this study cannot tell us
Small sample size (N=197) limits statistical power. Urine metabolites capture only recent exposure, not cumulative prenatal burden. Observational design with multiple comparisons raises risk of chance findings. Effect modification by sex and cannabis needs replication. Atlanta-specific cohort may not generalize.
How to read the evidence
Prospective cohort with biomarker-confirmed exposures and sophisticated mixture analysis, but small sample and multiple comparisons limit confidence.
When this study was published
Published 2025.
The bigger picture
Most prenatal cannabis research focuses on THC alone, ignoring the contaminants present in cannabis products. This study suggests that the real-world picture is more complex: the insecticides on cannabis and tobacco plants may be contributing to (or modifying) the neurodevelopmental effects attributed to the substances themselves.
Questions still open
- Whether pesticide contamination of cannabis products contributes to adverse prenatal outcomes typically attributed to cannabis itself
- How prenatal co-exposure patterns differ between states with regulated versus unregulated cannabis markets
Common questions
Was cannabis harmful to the babies?
Are insecticides on cannabis a known problem?
Read the original research
Associations of prenatal tobacco and insecticide co-exposures with neurobehavioral responses among children born to pregnant women exposed to cannabis.
Neurotoxicology and teratology, 111, 107536
Citation
Sehgal, Neha; Brennan, Patricia A; Dunlop, Anne L; Liang, Donghai; Corwin, Elizabeth J; Tan, Youran; Everson, Todd M; Caudle, W Michael; Panuwet, Parinya; D'Souza, Priya E; Yakimavets, Volha; Lee, Grace E; Barr, Dana Boyd; Eick, Stephanie M. (2025). Associations of prenatal tobacco and insecticide co-exposures with neurobehavioral responses among children born to pregnant women exposed to cannabis.. Neurotoxicology and teratology, 111, 107536. https://doi.org/10.1016/j.ntt.2025.107536
Explore the wider topic
- How to Talk to Your Teenager About Weed (Without Losing Them)
- My Kid's Friends Smoke Weed: A Parent's Guide
- I Smoke Weed But Don't Want My Kids To: Navigating the Hypocrisy
- Quitting Weed as a Parent: Why It Is the Hardest and Most Important Quit
- Quitting Weed as a Teen or Young Adult
- My Kid Is Smoking Weed: A Parent's Guide