The value of Sonographic measurement of cervical length and fetal fibronectin testing in predicting preterm delivery

Objective: The aim of this study was to determine whether the combination of both fetal fibronectin and sonographic measurement of cervical length in women with preterm labor provides a better prediction than the individual tests alone. Methods: We examined 40 women with singleton pregnancies presenting at 24-35 (median 31) weeks of gestation with regular and painful uterine contractions, intact membranes and cervical dilatation of less than 3 cm. On admission to the hospital, fetal fibronectin positivity in cervicovaginal secretions was determined and transvaginal sonographic measurement of cervical length was carried out. The primary outcome measure was delivery within 14 days of presentation. Results: Total of 40 eligible women at a mean gestational age of 28,3 +/- 4,8 weeks were enrolled from a population of 196 subjects screened. The overall prevalence of preterm delivery <37 weeks was 65%. Positive fetal fibronectin was found in 62,5% of patients and and cervical length of 30 mm or less in 55%. The sensitivity, specificity, and positive and negative predictive values of cervical length <= 30 mm, and of fetal fibronectin >= 50 ng/mL were 77%, 78%, 63%, and 88%, respectively. Conclusions: Combined the assessment of fetal fibronectin in cervico-vaginal secretions and the sonographic cervical length measurement improve the prediction of preterm delivery within 14 days in women with threatened preterm labor