Cell Study Reveals Pregnancy Risk Insights

UC San Francisco scientists map maternal-fetal connection in unprecedented detail

Apr. 9, 2026 at 1:28am by Ben Kaplan

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An abstract, highly structured painting in soft, earthy tones depicting the complex cellular interactions and biological forces at the maternal-fetal interface, conveying the structural complexity of this critical biological process.A conceptual illustration of the intricate cellular landscape at the maternal-fetal interface, revealing new insights into healthy pregnancies and potential causes of complications.San Francisco Today

Researchers at the University of California, San Francisco have created a detailed atlas of the cells involved in the maternal-fetal interface, the critical biological connection between a pregnant woman and her developing baby. The study, published in Nature, identified a previously unknown maternal cell type that may help regulate placental cell invasion and be linked to poorer pregnancy outcomes associated with cannabis use.

Why it matters

This research provides an unprecedented look at the complex cellular interactions that support a healthy pregnancy and could lead to a better understanding of conditions like preeclampsia, preterm birth, and miscarriage. The findings suggest new potential targets for treating pregnancy complications.

The details

Using advanced single-cell and spatial analysis tools, the UCSF team examined about 200,000 individual cells from uterine and placental tissue, mapping different cell types and how they develop over the course of pregnancy. They discovered a previously unknown maternal cell type located where fetal placental cells first enter the uterus, which appears to regulate placental cell invasion - a critical process for establishing blood flow to the fetus. The researchers also found that exposing these cells to cannabinoid molecules caused them to further restrict placental cell invasion, potentially explaining links between cannabis use and poorer pregnancy outcomes.

  • The study was published on April 8, 2026.

The players

Jingjing Li

PhD, associate professor in UCSF's Department of Neurology and the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, and the senior author of the study.

Susan J. Fisher

PhD, professor of Obstetrics, Gynecology and Reproductive Sciences at UCSF and co-leader of the study.

Cheng Wang

PhD, the study's first author.

University of California, San Francisco (UCSF)

The university where the research was conducted.

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What they’re saying

“This work gives us a much clearer picture of this critical region than ever before.”

— Jingjing Li, Associate Professor, UCSF

“By examining this tissue cell by cell across pregnancy, we can begin to understand both normal development and what may go wrong.”

— Susan J. Fisher, Professor, UCSF

“Population studies have linked cannabis use during pregnancy to poorer outcomes. This cell type may help explain the biological basis of that association.”

— Cheng Wang, PhD, Study First Author

What’s next

The researchers plan to further study complicated pregnancies to identify potential targets for treatment based on the detailed map of healthy pregnancies they have established.

The takeaway

This groundbreaking research provides unprecedented insights into the complex cellular interactions that support a healthy pregnancy, opening new avenues for understanding and potentially treating conditions like preeclampsia, preterm birth, and miscarriage.