Prognostic value of cervical distensibility index measurement in the outcome of pregnancies with threatened premature labor.

Threatened premature labor remains a difficult diagnostic and therapeutic problem, and various clinical scores have been designed to evaluate its prognosis. This study presents the use of a cervicotonometer to measure cervical distensibility in 58 women hospitalized for threatened premature labor. This value will be used to determine whether preterm labor is preceded by preterm cervical maturation and thus to assess prognosis. The cervical distensibility index (CDI) obtained with the cervicotonometer was significantly elevated at the time of hospitalization in women who had a preterm delivery when compared to those who delivered at or after 37 weeks of amenorrhea, whereas clinical scores showed no difference between these two groups. No preterm deliveries occurred when the CDI was normal or low at the time of hospitalization. Therefore, CDI measurement, reflecting cervical maturation, seems to be a good prognostic indicator in premature labor.

Mechanical properties of the pregnant human uterine cervix use of an instrument to measure the index of cervical distensibility.

An instrument has been designed and manufactured to measure precisely in clinical practice the distensibility index of the human uterine cervix expressed as centimeters per kilogram. Operation of the instrument and possible errors measuring the cervical distensibility index in nonpregnant patients, during gestation and during the postpartum period, are presented. The ability to easily quantify the mechanical characteristics of the uterine cervix in humans throughout gestation will now allow one to carry out precise studies concerning pharmacologically induced cervical maturation or pathological modifications of the uterine cervix in cervical incompetence or threatened premature labor.