RESUMO
OBJECTIVE: We performed the transvaginal ultrasonographic evaluation of uterine cervix and fetal fibronectin in cervicovaginal secretions in women after 37 complete weeks of gestation to predict the onset of labor. METHODS: Total 80 primiparous or multiparous women were divided into two groups on the duration between evaluation and onset of labor. The biometric analysis of uterine cervix(cervical index, endocervical length, funneling, funnel length and width) was done by transvaginal ultrasonography. The cervicovaginal fetal fibronectin was measured by fetal fibronectin immunoassay (ELISA kit, Adeza Biochemical, USA). The efficacy of these method was analyzed with Pearson chi-square test, receiver-operator characteristic curves, and multiple logistic regression test. RESULTS: 1) There were no significant differences in clinical characteristics between two groups. 2) Group 1(onset of labor within 7 days after evaluation) showed significantly shorter endocervical length(Group 1: 2.33+/-0.75cm,Group 2: 2.93+/- 0.42cm, p=0.013), higher value of cervical index(Group 1: 1.27+/-0.67, Group 2: 0.62+/-0.34, p=0.008) and higher level of fetal fibronectin(Group 1: 98.65+/-11.34ng/ml, Group 2: 13.37+/- 2.7ng/ml, p=0.004). 3) The ROC curve analysis showed that a level of endocervical length 0.7, fetal fibronectin> 60ng/ml had the diagnostic performance in predicting group 1. Fetal fibronectin level in cervicovaginal secretion> 60ng/ml showed the highest diagnostic index in predicting the onset of labor within 7 days(p<0,001, odds ratio=21.3). CONCLUSION: Cervicovaginal fetal fibronectin predicts delivery within 7 days more accurately than cervical index, endocervical length. Combine use of these tests improve the diagnostic efficiency and allowed prediction of onset of labor, identifying a subgroup of patients who may require aggressive treatment.