Interval evaluation of the cervix for predicting pregnancy outcome and diagnosing cervical incompetence.

The purpose of this study was to relate cervical compliance in the nonpregnant state to previous obstetric outcome in women with histories of early deliveries and to the length of gestation in subsequent pregnancies. One hundred eighty-four women with histories of spontaneous second-trimester abortions or early preterm deliveries had cervical evaluations in the interval state. Hysterography, catheter traction and dilator passage tests were utilized to generate a cervical compliance score, which was related to the weeks' gestation and clinical presentation in early delivery and to the length of gestation in subsequent pregnancies. Women with high scores (less cervical resistance) delivered their index pregnancies earlier in gestation than did women with low scores and were more likely to have presented with clinical cervical incompetence. In subsequent pregnancies, only 9% of pregnancies entering the second trimester in women with low scores delivered at < 30 weeks' gestation as compared with 24% in those with high scores. The evaluation of cervical compliance in the nonpregnant state is predictive of subsequent pregnancy outcome and therefore is a useful adjunct to the clinical history in diagnosing cervical incompetence.