Prediction of preterm birth by fetal fibronectin combined with cervical length measurement

Objective To explore the predictive value of fetal fibronectin(fFN) combined with cervical length measurement for preterm birth.Methods A total of 124 pregnant women with threatened preterm birth were enrolled in this study.All cases were assigned into two groups:preterm group(n=44) and full-term group(n=80).The cervical length was measured by ultrasonography.The fFN expression was detected by double-antibody sandwich immunosorbent assay.Results The positive rates of fFN in preterm group and full-term group were 72.7% and 22.5%,respectively,which was higher in preterm group than that in full-term group(P0.05).The preterm delivery was predicted by fFN with sensitivity 72.7%(32/44),specificity 77.5%(62/80),missed diagnosis rate 27.3%(12/44),misdiagnosis rate 22.5%(18/80),positive predictivevalue of 64.0%(32/50),and negative predictive value 83.8%(62/74).The average cervical length in preterm group and full-term group were(21.34±5.08)mm and(29.59±5.46)mm,respectively,which was shorter in preterm group than that in full-term group(P0.05).The preterm delivery was predicted by cervical length measurement with sensitivity 68.2%(30/44),specificity 76.2%(61/80),missed diagnosis rate 31.8%(14/44),misdiagnosis rate 23.8%(19/80),positive predictive value 61.2%(30/49),and negative predictive value 81.3%(61/75).The preterm delivery was predicted by fFN combined with cervical length measurement with sensitivity 90.9%(40/44),specificity 88.8%(71/80),missed diagnosis rate 9.1%(4/44),misdiagnosis rate 11.2%(9/80),positive predictive value 81.6%(40/49),and negative predictive value 94.7%(71/75),which was better than that predicted by fFN or cervical length(P0.05).Conclusion The fFN combined with cervical length measurement showed effectively to predict preterm birth,which was worthy of clinical application.