Daily THC Edibles During Pregnancy Impaired Placental Function in Rhesus Monkeys
Rhesus monkeys given daily THC edibles from before conception through pregnancy had significantly decreased amniotic fluid, reduced placental blood flow, lower fetal oxygen availability, and placental tissue damage compared to controls.
Quick Facts
What This Study Found
THC-exposed pregnancies showed significantly decreased amniotic fluid volume (p<0.001), reduced placental perfusion (p<0.05), and lower fetal oxygen availability (p<0.05). Placental tissue showed microinfarctions only in THC-exposed animals. RNA sequencing revealed disrupted blood vessel development and angiogenesis pathways.
Key Numbers
10 rhesus macaques (5 THC, 5 control). Imaging at G85, G110, G135, G155. THC group: significantly decreased amniotic fluid (p<0.001), placental perfusion (p<0.05), fetal oxygen availability (p<0.05). Microinfarctions found only in THC-exposed placentas. RNA-seq showed dysregulated vasculature development.
How They Did This
Controlled study in 10 rhesus macaques (5 THC, 5 control). THC group received daily THC edibles pre-conception through pregnancy. Serial ultrasound and MRI at four gestational timepoints. Cesarean delivery at gestational day 155 (near term) with placental collection for histology and RNA sequencing.
Why This Research Matters
This is the first primate study using advanced imaging to demonstrate that THC impairs placental function during pregnancy. The findings of reduced blood flow and oxygen delivery to the fetus have direct implications for human cannabis use during pregnancy.
The Bigger Picture
Rhesus macaques share similar placental biology with humans, making these findings particularly relevant. The convergence of reduced blood flow, lower oxygen, tissue damage, and disrupted vascular gene expression creates a compelling picture of placental insufficiency from THC exposure.
What This Study Doesn't Tell Us
Small sample size (5 per group). Daily THC edible dosing may not reflect all human use patterns. The study ended before natural delivery, so birth outcomes are unknown. A single THC preparation was used, not reflecting the variety of cannabis products.
Questions This Raises
- ?What are the downstream effects on offspring development after birth?
- ?Is there a dose threshold below which placental effects do not occur?
- ?Would CBD co-exposure modify the THC placental effects?
Trust & Context
- Key Stat:
- Placental microinfarctions found only in THC-exposed pregnancies
- Evidence Grade:
- Moderate: controlled primate study with advanced imaging and molecular analysis, though limited by small sample size.
- Study Age:
- Published in 2022.
- Original Title:
- Chronic prenatal delta-9-tetrahydrocannabinol exposure adversely impacts placental function and development in a rhesus macaque model.
- Published In:
- Scientific reports, 12(1), 20260 (2022)
- Authors:
- Roberts, Victoria H J(3), Schabel, Matthias C(2), Boniface, Emily R(4), D'Mello, Rahul J, Morgan, Terry K, Terrobias, Juanito Jose D, Graham, Jason A, Borgelt, Laura M, Grant, Kathleen A, Sullivan, Elinor L, Lo, Jamie O
- Database ID:
- RTHC-04173
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Is it safe to use cannabis during pregnancy?
This primate study found THC edibles during pregnancy caused reduced placental blood flow, lower fetal oxygen, and tissue damage. While animal studies do not always translate directly to humans, the similar placental biology of rhesus monkeys makes these findings concerning.
What is placental insufficiency?
Placental insufficiency means the placenta does not deliver enough blood, oxygen, and nutrients to the developing fetus. It can lead to low birth weight, preterm birth, and developmental problems. This study found signs of placental insufficiency in THC-exposed monkey pregnancies.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-04173APA
Roberts, Victoria H J; Schabel, Matthias C; Boniface, Emily R; D'Mello, Rahul J; Morgan, Terry K; Terrobias, Juanito Jose D; Graham, Jason A; Borgelt, Laura M; Grant, Kathleen A; Sullivan, Elinor L; Lo, Jamie O. (2022). Chronic prenatal delta-9-tetrahydrocannabinol exposure adversely impacts placental function and development in a rhesus macaque model.. Scientific reports, 12(1), 20260. https://doi.org/10.1038/s41598-022-24401-4
MLA
Roberts, Victoria H J, et al. "Chronic prenatal delta-9-tetrahydrocannabinol exposure adversely impacts placental function and development in a rhesus macaque model.." Scientific reports, 2022. https://doi.org/10.1038/s41598-022-24401-4
RethinkTHC
RethinkTHC Research Database. "Chronic prenatal delta-9-tetrahydrocannabinol exposure adver..." RTHC-04173. Retrieved from https://rethinkthc.com/research/roberts-2022-chronic-prenatal-delta9tetrahydrocannabinol-exposure
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.