Low concentrations of vaginal fetal fibronectin as a predictor of deliveries occurring after 41 weeks

OBJECTIVE: This study sought to determine whether low concentrations of fetal fibronectin in the cervical and vaginal secretions of patients at 39 weeks' gestation predicted pregnancies progressing beyond 41 weeks' gestation. STUDY DESIGN: A retrospective cohort study was undertaken using cervical and vaginal samples collected from 75 consenting patients during the thirty-ninth week of gestation. Levels of fetal fibronectin were measured by immunoassay. Demographic, obstetric, neonatal, and laboratory data were analyzed by Fisher's exact test, Student t test or Wilcoxon's rank-sum test, multiple logistic regression, and receiver-operating characteristic curve analysis. RESULTS: There was a 35.5-fold increase in vaginal fetal fibronectin concentrations among patients delivered at