[Vaginal ultrasound cervix imaging in pregnancy--predictive value of suspicious findings on the subsequent course of pregnancy].

To evaluate the use of serial measurement of cervical length and width of internal os by means of vaginal ultrasound 144 pregnant women were examined prospectively. We hypothesized, that cervical length and width of the internal os would be significantly different in normal patients and those with preterm labor or cervical incompetence. Predictive validity of suspicious findings indicating the occurrence of preterm labour and cervical incompetence in further course of pregnancy should be assessed. Anamnestic, sonographic and outcome data were analysed. To assess sensitivity, specifity, positive and negative predictive values, different values of cervical length and width of internal os between 20 and 27 weeks were analysed. Significant differences of cervical length and width of internal os in normal and pathologic pregnancies could be documented early in pregnancy course. By further investigation early suspicious findings indicating the developing pathology were found only for the subgroup with cervical incompetence. Sensitivity of vaginal ultrasound examination between 20 and 27 weeks indicating the whole pathologic collective was only 30%, whereas up to 55.5% of pregnancies complicated by cervical incompetence were detected. Specifity (up to 95%) and negative predictive value (90%) were high. The results show that cervical examination by vaginal ultrasound allows early detection of developing cervical incompetence. The high specifity and the high negative predictive value may be useful to exclude cervical incompetence in clinically unclear cases thus helping to avoid unnecessary therapeutical interventions.