Abstract

Fetal fibronectin, a large molecular weight glycoprotein produced in the chorion, is expressed in cervical and vaginal secretions in women with disruption of the choriodecidual [table: see text] junction by labor or by inflammation. The presence of FFN in vaginal or cervical secretions before 35 weeks is a moderately good predictor of preterm delivery. The absence of FFN is a strong predictor that preterm delivery is unlikely within the next 7 to 14 days, with NPVs exceeding 99% in some studies. The predictive power of FFN is stronger at earlier gestation ages (24-28 wks) than it is later [table: see text] in pregnancy and is stronger for short-term prediction (7-14 d) than for predicting overall outcome (however, it remains statistically significant for predicting delivery < 37 wks). Although use of FFN in the clinical setting may require some changes to common protocols (e.g., performing sterile speculum examination before digital cervical examination), the use of FFN in patients with suspected preterm labor appears to have significant utility in reducing unnecessary interventions in women with symptoms suggestive of preterm labor. In women without symptoms, the use of FFN may be most beneficial in providing reassurance to some women thought to be at high-risk for preterm delivery because of past obstetric history. Screening women without symptoms at low-risk with FFN is not yet recommended because effective interventions are not demonstrated for patients found to be positive.