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Updated: May 15, 2026
04:18
Modeling Ascending Vaginal Infection, Preterm Birth, and Neonatal Morbidity in Mice
Published on: October 10, 2025
Fetal sex and preterm birth
J Challis1, J Newnham, F Petraglia
1University of Toronto, Dept Obstetrics and Gynecology, Mount Sinai Hospital, Samuel Lunenfeld Research Institute, Toronto, ON, Canada. j.challis@utoronto.ca
Placenta
|December 25, 2012
Summary
Male fetuses may increase preterm birth risk due to a more pro-inflammatory placental environment. This sex-specific difference impacts pregnancy outcomes and fetal health.
Area of Science:
- Reproductive biology
- Immunology
- Genetics
Background:
- Preterm birth rates vary across populations and ethnic groups.
- Epidemiological studies indicate a higher incidence of preterm birth in male pregnancies.
- This male:female difference is more pronounced in earlier preterm births.
Purpose of the Study:
- To investigate sex-specific differences in placental inflammatory responses.
- To explore the molecular mechanisms underlying sex-biased preterm birth.
- To assess the impact of fetal sex on placental gene expression and function.
Main Methods:
- Comparison of placental or chorion trophoblast cell responses to LPS stimulation between male and female fetuses.
- Measurement of pro-inflammatory (TNFα) and anti-inflammatory (IL-10, G-CSF) cytokine production.
- Analysis of sex-dependent gene expression, including PTGS-2, PGDH, and 11β hydroxysteroid dehydrogenase-2.
Main Results:
- Placental cells from male fetuses produced more TNFα and less IL-10 and G-CSF in response to LPS.
- Cells from male pregnancies showed higher PTGS-2 and lower PGDH expression.
- Fetal sex influences placental gene expression and the potential for a pro-inflammatory environment.
Conclusions:
- The presence of a male fetus may promote a more pro-inflammatory placental environment.
- Sex-dependent maturation of fetal axes and placental gene expression contribute to these differences.
- These findings necessitate consideration in preterm labor diagnosis and personalized perinatal care strategies.
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