Steroid concentrations in human cervical tissue in relation to cervical ripening.

Steroid concentrations in human cervical tissue were measured in order to study the mechanism of cervical ripening at term. Thirty-four women at 37 to 41 weeks of gestation were selected for the study and divided into two groups. Group A consisted of 21 cases with ripened cervix, and Group B consisted of 13 cases with non-ripened cervix. The condition of the cervix was judged by the Bishop's Score. Free and conjugated estrone (E1), estradiol (E2), estriol (E3), and dehydroepiandrosterone (DHA) concentrations in cervical tissue were measured by radioimmunoassay (RIA). Significantly higher concentrations of free E1, conjugated E2, E3 and DHA were found in Group A than in Group B. Cervical tissue during labor showed a further increase in the concentrations of these steroids. Pronounced increases of the steroid concentrations were noted following DHA-Sulfate (DHA-S) administration. These results suggest an intimate relationship between cervical ripening and steroid concentrations in cervical tissue during pregnancy.