Evaluation of fetal fibronectin rapid bedside test as a predictor of preterm labour: a prospective study

ABSTRACT

Background: Preterm birth defined as birth before 37 weeks of gestation is a significant public health issue. Identification of patients at risk of preterm labour while ruling out those who are not is a fundamental but challenging goal for clinicians. This study was done to evaluate bed side dipstick test for detecting fetal fibronectin in cervico-vaginal secretions as a predictor of preterm delivery in symptomatic and asymptomatic high risk group.Methods: This was a hospital based prospective, double blinded study. We enrolled 100 pregnant women presenting with or without symptoms of preterm delivery, between 20 and 35 weeks of gestation. A rapid bed side dipstick test was performed to detect FFN in cervico-vaginal secretions of all enrolled women (symptomatic and asymptomatic high risk women) and results were evaluated for prediction of preterm labour. Qualitative data were analyzed by using Chi-square and Fisher’s exact test and quantitative data were analyzed by using unpaired Student’s t test and Mann-Whitney test. P value < 0.05 was considered significant.Results: In symptomatic group sensitivity, specificity, PPV and NPV of FFN test in predicting delivery within 48 hours, 7days 14days and preterm delivery was 100%, 63.2%, 46.2%, 100%; 100%, 72.7%, 65.4%, 100%; 100%, 75%, 69.2%, 100%; 80%, 76%, 76.9%, 79.2% respectively. In asymptomatic high risk group, sensitivity, specificity, PPV and NPV of FFN test in predicting preterm delivery (<37weeks) was 0%, 87.5%, 0%, 77.8%.Conclusions: The high negative predictive value may be of value in avoiding unnecessary interventions with potentially hazardous medications and identifying symptomatic women who are not in true labour and also allaying anxiety of asymptomatic high risk women.