Fetal fibronectin for evaluation of preterm labor in the setting of cervical cerclage.

Objective: To evaluate the efficacy of fetal fibronectin (fFN) testing in cervical cerclage patients presenting with acute signs or symptoms of preterm labor.

Methods: A total of 71 fFN tests were performed in 48 women between 23 and 34 weeks' gestation who presented at two institutions at risk for imminent delivery with cerclage in situ.

Results: The sensitivity, specificity, positive predictive value, and negative predictive value for delivery within 2 weeks of fFN testing were 100, 77, 28 and 100%, respectively. For delivery before 34 weeks sensitivity, specificity, positive predictive value, and negative predictive value were 91, 78, 56 and 97%, respectively. The relative risk of delivery <34 weeks with positive fFN was 16.7 (P < 0.001).

Conclusions: For patients with cervical cerclage, fFN testing is a valid diagnostic tool in the evaluation of preterm labor.