Inflammation in the female reproductive tract may make it difficult to conceive a child, but replenishing a key hormone could keep inflammation in check, according to researchers from the University of Missouri School of Medicine.

The study is published in the journal Science Advances.

Progesterone, nicknamed the “pregnancy hormone,” is crucial for embryo growth, the first stage of fetal development. Using a mouse model, researchers found that if the body does not have enough proteins to respond to progesterone, there is also increased inflammation. It’s still unclear if these low protein levels cause inflammation to occur.

“What we do know is that inflammation is bad for embryo development,” study author Joy Winuthayanon said. “Embryos are highly sensitive to any stressors in their environment. When we treated the inflammation, more embryos survived long enough to implant themselves in the uterus.”

These findings could help improve women’s chances of becoming pregnant. More than 60% of pregnancy losses occur in the first 4–6 weeks, which is often before most patients are aware they are pregnant. Understanding the early stages of the embryo’s development could help save more pregnancies, especially for women with certain conditions like pelvic inflammatory disease.

“Women with low progesterone or inflammation in the reproductive system typically have more difficulty conceiving and becoming pregnant,” co-author Dr. Mark Hunter said. “This research presents a potential explanation and opens the door to possible treatments.”

Winuthayanon says future research will focus on developing effective, convenient and noninvasive anti-inflammatory treatments, which could include a new medication or an injection.

“Currently, we are planning to investigate how targeting specific inflammatory pathways in the female reproductive tract might improve the development of embryos and implantation success,” Winuthayanon said.

Wipawee “Joy” Winuthayanon, BSN, Ph.D. is an associate professor of Obstetrics, Gynecology and Women’s Health at the MU School of Medicine and a NextGen Precision Health Investigator. Mark Hunter, MD, is a gynecologic oncologist at MU Health Care, an associate professor at the MU School of Medicine and the Director of the Division of Gynecologic Oncology.