Cannabis Use During Pregnancy Altered Fetal Brain Connectivity Patterns
Fetal brain imaging of 115 fetuses found that prenatal cannabis exposure was associated with altered hippocampal connectivity to frontal, temporal, and cingulate brain regions, with patterns linked to less favorable developmental outcomes.
Quick Facts
What This Study Found
Fetuses exposed to cannabis prenatally showed altered hippocampal connectivity to dorsolateral, medial, and superior frontal cortex, insula, anterior temporal, and posterior cingulate regions. The connectivity patterns in exposed fetuses were more often associated with less favorable outcomes at age 5.
Key Numbers
115 fetuses; mean gestational age 32.2 weeks; 43% female; cannabis-exposed group showed altered connectivity to frontal, temporal, insular, and cingulate regions; connectivity patterns in exposed group linked to less favorable age-5 outcomes.
How They Did This
Prospective fetal fMRI study of 115 fetuses (mean 32.2 weeks gestation, 43% female) with prenatal drug toxicology data, using voxelwise hippocampal connectivity analysis in age- and sex-matched subsets.
Why This Research Matters
This is among the first studies to show that prenatal cannabis exposure may alter brain connectivity before birth, suggesting that developmental effects begin in utero rather than emerging only after delivery.
The Bigger Picture
If cannabis is altering fetal brain wiring during a critical period of development, it provides a biological mechanism for the behavioral and cognitive differences observed in children with prenatal cannabis exposure.
What This Study Doesn't Tell Us
Small sample for subgroup analyses; fetal fMRI is technically challenging with potential motion artifacts; cannot separate cannabis effects from other co-occurring factors; outcome classification at age 5 was preliminary.
Questions This Raises
- ?Do these fetal connectivity changes persist into childhood?
- ?Is there a threshold of prenatal cannabis exposure below which connectivity remains normal?
Trust & Context
- Key Stat:
- Prenatal cannabis exposure altered fetal brain connectivity patterns linked to less favorable developmental outcomes
- Evidence Grade:
- Novel fetal neuroimaging study with preliminary evidence, limited by small subgroup sizes and technical challenges of fetal fMRI.
- Study Age:
- Fetal imaging with age-5 outcome follow-up.
- Original Title:
- Miswiring the brain: Human prenatal Δ9-tetrahydrocannabinol use associated with altered fetal hippocampal brain network connectivity.
- Published In:
- Developmental cognitive neuroscience, 51, 101000 (2021)
- Authors:
- Thomason, Moriah E, Palopoli, Ava C, Jariwala, Nicki N, Werchan, Denise M, Chen, Alan, Adhikari, Samrachana, Espinoza-Heredia, Claudia, Brito, Natalie H, Trentacosta, Christopher J
- Database ID:
- RTHC-03576
Evidence Hierarchy
Enrolls participants and follows them forward in time.
What do these levels mean? →Frequently Asked Questions
Does cannabis during pregnancy affect the baby's brain before birth?
This study found altered brain connectivity patterns in fetuses exposed to cannabis, particularly in connections between the hippocampus and frontal brain regions. These patterns were associated with less favorable developmental outcomes at age 5.
What parts of the brain were affected?
Cannabis exposure was associated with altered connectivity from the hippocampus (important for memory) to frontal regions (important for decision-making), the insula (emotional processing), and the cingulate cortex (attention and emotion regulation).
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-03576APA
Thomason, Moriah E; Palopoli, Ava C; Jariwala, Nicki N; Werchan, Denise M; Chen, Alan; Adhikari, Samrachana; Espinoza-Heredia, Claudia; Brito, Natalie H; Trentacosta, Christopher J. (2021). Miswiring the brain: Human prenatal Δ9-tetrahydrocannabinol use associated with altered fetal hippocampal brain network connectivity.. Developmental cognitive neuroscience, 51, 101000. https://doi.org/10.1016/j.dcn.2021.101000
MLA
Thomason, Moriah E, et al. "Miswiring the brain: Human prenatal Δ9-tetrahydrocannabinol use associated with altered fetal hippocampal brain network connectivity.." Developmental cognitive neuroscience, 2021. https://doi.org/10.1016/j.dcn.2021.101000
RethinkTHC
RethinkTHC Research Database. "Miswiring the brain: Human prenatal Δ9-tetrahydrocannabinol ..." RTHC-03576. Retrieved from https://rethinkthc.com/research/thomason-2021-miswiring-the-brain-human
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.