Accuracy of cervico-vaginal fetal fibronectin test in predicting the risk of spontaneous preterm birth—a systematic review

Abstract

We studied the accuracy with which the cervico-vaginal fetal fibronectin test predicts spontaneous preterm birth in asymptomatic and symptomatic pregnant women. This was a systematic quantitative review of test accuracy studies. Two reviewers selected and extracted data on study characteristics, quality and accuracy independently. Accuracy data were used to form 2 × 2 contingency tables with spontaneous preterm birth before 34 and 37 weeks’ gestation and birth within 7–10 days of testing (only for symptomatic pregnant women) as reference standards. Data were pooled to produce summary receiver operating characteristic (ROC) curves and summary likelihood ratios for positive (LR+) and negative (LR−) test results. There were 64 primary articles consisting of 28 accuracy studies in asymptomatic women and 40 accuracy studies in symptomatic women, including a total of 22 390 women. Among asymptomatic women, the best summary LR+ was 4.01 (95% confidence interval 2.93–5.49) for predicting birth before 34 weeks’ gestation, with corresponding summary LR− of 0.78 (0.72–0.84). Among symptomatic women, the best summary LR+ was 5.42 (4.36–6.74) for predicting birth within 7–10 days of testing, with corresponding summary LR− of 0.25 (0.20–0.31).