Fetal Fibronectin in Cervical and Vaginal Secretions as a Predictor of Preterm Delivery

Abstract Background. Preterm delivery is the leading cause of neonatal mortality in the United States, but efforts to address the problem are hampered by the inability to predict accurately which pregnancies are at risk. We postulated that damage to the fetal membranes may release fetal fibronectin into the cervix and vagina, giving rise to a biochemical marker for preterm delivery. Methods. We measured fetal-fibronectin concentrations in cervical and vaginal secretions, amniotic fluid, and maternal plasma with a sensitive immunoassay using the monoclonal antibody FDC-6. Immunohistochemical studies were used to determine the distribution of fetal fibronectin in the placenta and amniochorionic membranes and to ascertain its cell of origin. Results. Women with uncomplicated pregnancies (n = 163) who delivered at term rarely had cervicovaginal fetal-fibronectin concentrations above 0.05 μg per milliliter between 21 and 37 weeks of gestation (11 of 267 cervical samples [4 percent] and 9 of 267 vaginal samples...