Completed Research

This was a prospective study involving singleton pregnancies presenting at 20-36 weeks of gestation with symptoms of threatened preterm labour, aimed at assessing the effectiveness of the fetal fibronectin (fFN) test in combination with cervical length measurement for predicting spontaneous preterm birth (sPTB) in women presenting with threatened preterm labour. In this study, sonographic cervical length and quantitative fFN levels in cervicovaginal secretions were measured upon admission. Logistic regression analysis was performed to develop the following models: cervical length alone, fFN at various thresholds, and their combined models for predicting sPTB, sPTB within 7 days, and 14 days. The area under the receiver operating characteristic curve (AUROC), positive predictive value (PPV), negative predictive value (NPV), and detection rates at fixed false-positive rates (FPRs) of 5% and 10% were calculated. We found that in a total of 398 cases analysed, there were 55 (13.8%) cases of sPTB at <37 weeks of gestation. Of these, 22 cases (40.0%) and 27 cases (49.1%) delivered within 7 and 14 days of assessment, respectively. Shorter cervical length and increased fFN levels were associated with a higher risk of sPTB, sPTB within 7 days, and 14 days. The fFN test, at ≥50 ng/mL or ≥200 ng/mL, was superior to ≥500 ng/mL for predicting sPTB. The fFN test demonstrated comparable performance to cervical length alone for predicting sPTB. For predicting sPTB and sPTB within 14 days, the addition of fFN ≥50 ng/mL to cervical length achieved significantly higher AUROC compared to cervical length alone. For predicting sPTB within 7 days, adding the fFN test ≥50 ng/mL to cervical length increased the PPV from 36.7% (95% CI 19.9–56.1) to 44.1% (95% CI 27.2–62.1) at a fixed 5% FPR; adding cervical length to the fFN test alone also demonstrated a significant improvement in AUROC. In conclusion, in women symptomatic of threatened preterm labour, a combination of fFN and cervical length has improved the predictive performance for sPTB compared to either measure alone. Future prospective studies are needed to externally validate these findings in a diverse population.