Prenatal tobacco-cannabis co-exposure linked to blunted emotional responses in toddler boys
In a study of 247 mother-infant dyads, boys exposed to both tobacco and cannabis prenatally showed blunted emotional reactivity as toddlers, while continued postnatal cannabis exposure was associated with heightened reactivity.
Quick Facts
What This Study Found
Prenatal tobacco-cannabis co-exposure had a direct effect on blunted toddler reactivity in males only. Mothers who used substances had the highest anger/hostility and mood unpredictability. Continued postnatal cannabis exposure was associated with higher toddler reactivity. Prenatal anger/hostility and mood unpredictability predicted higher infant reactivity, which in turn predicted higher toddler reactivity.
Key Numbers
247 dyads at recruitment, 190 at toddler assessment; direct effect of co-exposure on blunted male toddler reactivity; highest anger/hostility and mood unpredictability in substance-using mothers; postnatal cannabis exposure associated with higher toddler reactivity
How They Did This
Prospective longitudinal study of 247 dyads recruited during the first trimester into tobacco-using (including cannabis co-users) and non-substance-using groups. Maternal mood, substance use, and infant/toddler reactivity were assessed across multiple time points using structural equation modeling.
Why This Research Matters
The sex-specific blunting effect of prenatal co-exposure, combined with the heightening effect of continued postnatal cannabis exposure, suggests complex developmental pathways that differ for boys and girls.
The Bigger Picture
Emotional reactivity in toddlerhood has implications for later behavioral regulation and mental health. Understanding how prenatal substance exposure shapes these early responses can inform early intervention.
What This Study Doesn't Tell Us
Cannot fully separate tobacco and cannabis effects in co-users; maternal mood confounds substance exposure effects; relatively small subgroups; observational design with potential unmeasured confounders; attrition from 247 to 190
Questions This Raises
- ?Why does prenatal co-exposure blunt reactivity in boys specifically?
- ?Does the blunted reactivity persist into childhood?
- ?Could targeting postnatal cannabis use reduce toddler emotional dysregulation?
Trust & Context
- Key Stat:
- 247 dyads tracked from first trimester through toddlerhood
- Evidence Grade:
- Prospective longitudinal design with prenatal recruitment and multiple assessments, though limited by inability to isolate individual substance effects.
- Study Age:
- 2024 study
- Original Title:
- Prenatal tobacco and tobacco-Cannabis co-exposure and unpredictability in maternal anger/hostility: Implications for toddler reactivity.
- Published In:
- Neurotoxicology and teratology, 106, 107399 (2024)
- Authors:
- Kelm, Madison R, Schuetze, Pamela(4), Eiden, Rina D(8)
- Database ID:
- RTHC-05421
Evidence Hierarchy
Watches what happens naturally without intervening.
What do these levels mean? →Frequently Asked Questions
How did prenatal substance exposure affect toddler emotions?
Boys exposed to both tobacco and cannabis before birth showed blunted emotional reactivity as toddlers, meaning their emotional responses were dampened. Girls did not show this effect. Meanwhile, continued cannabis exposure after birth was associated with increased reactivity in toddlers.
Did maternal mood play a role?
Yes. Mothers who used substances had the highest levels of anger/hostility and mood unpredictability during pregnancy. These mood factors independently predicted higher reactivity in infancy, which then carried forward into toddlerhood.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-05421APA
Kelm, Madison R; Schuetze, Pamela; Eiden, Rina D. (2024). Prenatal tobacco and tobacco-Cannabis co-exposure and unpredictability in maternal anger/hostility: Implications for toddler reactivity.. Neurotoxicology and teratology, 106, 107399. https://doi.org/10.1016/j.ntt.2024.107399
MLA
Kelm, Madison R, et al. "Prenatal tobacco and tobacco-Cannabis co-exposure and unpredictability in maternal anger/hostility: Implications for toddler reactivity.." Neurotoxicology and teratology, 2024. https://doi.org/10.1016/j.ntt.2024.107399
RethinkTHC
RethinkTHC Research Database. "Prenatal tobacco and tobacco-Cannabis co-exposure and unpred..." RTHC-05421. Retrieved from https://rethinkthc.com/research/kelm-2024-prenatal-tobacco-and-tobaccocannabis
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.