Progesterone Imbalance Influences Preterm Birth and Prolonged Labor

Researchers discover that an imbalance in progesterone signals can result in some pregnant women experiencing preterm or prolonged labor. The study was conducted on mice. Progesterone is a pregnancy hormone that helps prevent the uterus from contracting and going into premature labor. Progesterone receptor types A and B (PGR-A and PGR-B) are responsible for this.

Francesco DeMayo, senior author, said, "We used genetically engineered mouse models to alter the ratio of PGR-A and PGR-B in the muscle compartment of the uterus, called the myometrium. Our team found that PGR-A promotes muscle contraction and PGR-B prevents such contraction, and we identified the biological pathways influenced by both forms."

Results further discovered new molecules controlling uterine muscle contraction, which could serve as future therapeutic targets.

Prior research has shown that PGR-A regulates processes involved in initiating childbirth and that PGR-B affects molecular pathways related to maintaining the normal pregnancy course.

Preterm birth is the primary cause of neonatal morbidity and mortality, affecting 10 % of pregnancies worldwide. Prolonged labor increases the risks of infection, neonatal distress, and uterine rupture.

The researchers noted that care for preterm deliveries involves high social and economic costs, with premature infants being at greater risk for experiencing disorders ranging from blindness to cerebral palsy. At the same time, prolonged labor can harm both mother and infant and result in cesarean delivery.

Steve Wu, first author, said, “Progesterone treatment aimed at preventing premature labor can help a subset of patients, but for other individuals, confounding factors may reduce effectiveness.”

He added that findings might help advance labor dystocia (abnormally slow or protracted labor) treatment.

"Although labor stimulation by oxytocin infusion is an approved measure to mitigate labor dystocia, serious side effects have been associated with this treatment," said Wu. " Novel proteins that we identified as being part of progesterone signaling could serve as a key molecular switch of uterine contraction, through drug-dependent regulation of their activities," he explained.

Mary Peavy, co-first author, added, "Hormone signaling in pregnancy is complicated and involves both the hormone levels and the types of receptors in the uterus that sense the hormones. This publication sheds light on how hormones influence labor and can thus be used to help women when the uterus goes into labor too soon or for a prolonged period."



Source-Eurekalert