Avaliação do Risco de Parto Prematuro: Teste da Fibronectina Fetal e Medida do Colo Uterino Evaluation of Risk for Preterm Delivery by Fetal Fibronectin Test and Measurement of Uterine Cervix

SUMMARY Purpose: to evaluate the risk of preterm delivery using thefetal fibronectin test and the measurement of the cervix bytransvaginal ultrasonography in pregnant women withprevious preterm delivery. Methods: one hundred and seven women were enrolled inthe study at 24th, 28thand 32ndweek to detect the presenceof fetal fibronectin by immediate-reading membrane test andto perform vaginal ultrasonography to measure the lengthof the cervix between the internal and external cervical os.The cervix was considered to be short when the cervicallength was at or below the cutoff set by the receiver-operating characteristic (ROC) curve for prediction ofpreterm delivery. Sonographic cervical length and fetalfibronectin were compared to assess the risk of preterm birthbefore 34 and 37 weeks. Results: the spontaneous preterm delivery rate was 37.4%(40/107). The analysis made by the ROC curve indicated30 mm as the best cutoff to maximize sensitivity andspecificity at 24 and 28 weeks and 25 mm at 32 weeks ofgestation. The positive test of fetal fibronectin had asignificant relative risk (RR: 1.77; 95% confidence interval(IC): 1.10-2.84) to predict delivery before 37 weeks, whencompared with a negative test, only at 28 weeks. The