Maternal COVID-19 Infection Induces Placental Stress Responses That Strengthen Fetal Protection

Recent research published in the American Journal of Obstetrics & Gynecology reveals that COVID-19 infection in pregnant women triggers specific stress responses in the placenta, particularly within the syncytiotrophoblasts—the outermost fetal cell layer. These stress responses involve the activation of genes associated with preeclampsia, a pregnancy complication characterized by high blood pressure and organ damage. Notably, this response promotes cell proliferation in the placenta, which reinforces the maternal-fetal barrier and might help prevent the virus from reaching the fetus.

The study was conducted by researchers at Baylor College of Medicine, UTHealth Houston, and collaborating institutions. They found that the maternal immune response, especially the cytokine storm caused by COVID-19, impacts placental cells. Since direct infection of the placenta by the virus is rare, the stress responses are primarily driven by maternal inflammation rather than direct viral invasion.

To investigate these effects, scientists employed single-nucleus transcriptional profiling—a cutting-edge technique that allows detailed analysis of gene expression in fused multinucleated syncytiotrophoblasts, which are challenging to examine using traditional methods. Their analysis identified multiple distinct clusters of syncytiotrophoblasts, each responding differently to maternal inflammation.

This research was conducted during the early days of the pandemic, providing crucial insights into how COVID-19 affects placental health. The findings suggest that placental stress responses are a crucial part of the body's mechanism to maintain pregnancy health amid maternal infection. Understanding these responses can help improve management strategies for pregnant women during infectious outbreaks and highlight the importance of maternal immune regulation.

Overall, this study underscores the resilience of the placental barrier and provides a foundation for future research into maternal-fetal health during infectious diseases.

source: https://medicalxpress.com/news/2025-04-human-placenta-stress-response-maternal.html