Patterns of Plasma Corticotropin-Releasing Hormone, Progesterone, Estradiol, and Estriol Change and the Onset of Human Labor

Abstract

The very rapid rise of CRH in late pregnancy is associated with an E3 surge and critically altered P/E3 and E3/E2 ratios that create an estrogenic environment at the onset of labor. Our evidence provides a rationale for the use of CRH in predicting preterm birth and informs approaches to delaying labor using P supplementation.