Transvaginal cervical length and amniotic fluid index: Can it predict delivery latency following preterm premature rupture of membrane?

Abstract

Background: This study was performed to determine whether transvaginal cervical length (TVCL), amniotic fluid index (AFI), or a combination of both can predict delivery latency within 7 days in women presenting with preterm premature rupture of membranes (PPROMs). Materials and Methods: This was a prospective observational study of TVCL measurements in eighty singleton pregnancies with PPROM between 24–34 weeks. Transvaginal ultrasonography was performed to measure the CL and AFI. Delivery latency was defined as the period from the initial TVCL after PPROM to delivery of the baby, with our primary outcome being delivery within 7 days of TVCL. Sensitivity, specificity, and predictive values were used to test whether the presence of a short TVCL, AFI, or a combination of both affected the risk of delivery within 7 days. Results: The study showed that the validity of CL alone in predicting labor when the cutoff value = 2 cm, the sensitivity = 52.6%, specificity = 69%, positive predictive value (PPV) = 60.6%, negative predictive value (NPV) = 61.7%, and accuracy = 61.25%. The validity of AFI alone when the cutoff value = 5 cm, the sensitivity = 71.1%, specificity = 50%, PPV = 56.3%, NPV = 65.6%, and accuracy = 60%. With a combination of CL and AFI in predicting time of labor after PPROM, the following results were found: sensitivity = 50%, specificity = 92.8%, PPV = 86.4%, NPV = 67.2%, and accuracy = 72.5%. In women with PPROM, we found the ratio of gestational age (GA) ≤30 weeks who labored within 7 days as 44.7% and those labored more than 7 days as 55.3%. Conclusion: Our study showed that there was an increase in PPV when combining AFI and CL in the prediction of time of labor, so women with AFI ≤5 and CL ≤2 had 86.4% risk of delivery within 7 days after PROM. Furthermore, we found that there was no significant association between GA and parity with the prediction time of labor.