Prediction of preterm birth

The aim of this study was to assess the value of screening of cervical status in normal as well as in pregnancies with risk factors. 1327 pregnancies were studied prospectively; 16% had a medical history of earlier obstetrical or gynecological complications (group I) and 6% had complications during the first 24 weeks of the current pregnancy (group II). The remainder were considered low-risk pregnancies and randomly divided into groups III and IV. In groups I, II and III cervical scoring in accordance with Westin was performed in weeks 24, 28 and 32. The incidence of births before 37 weeks of gestation was 5.6% in group I, 8.8% in group II, 1.5% in group III and 0.7% in group IV. In presence of the risk factors, 61% of the spontaneous preterm deliveries were predicted early in pregnancy. The predictive value of a normal cervical score was high (about 95%) in all groups. In uncomplicated pregnancies the predictive value of a pathological score was only 4% and for cervical dilatation, 6%. In the risk groups the predictive value of a pathological cervix was 3-5-fold higher. Cervical examination in low-risk pregnancies does not improve prediction of preterms but is a complement in a system for indication for preterm delivery in women with defined risk factors.