Objective: Diagnosis of premature rupture of membranes (PROM) is difficult in equivocal cases with traditional methods. This study aimed to evaluate the reliability of vaginal washing fluid urea and creatinine for diagnosis of PROM and to determine the cut off value.
Materials and methods: The current study was a prospective case control. Women having gestational age of 28 to 42 weeks were divided into two equal groups: Fifty with history of leaking per vagina (study group) and an equal number with gestation matched none leaking (control group) were recruited. Data analysis was done by Student’s t-test, receiver operator curve and chi square test.
Results: The demographic data of both groups were comparable at the time of sampling (p > 0.05).Vaginal fluid urea and creatinine was significantly higher in study group (p < 0.001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of vaginal fluid urea with a cut off value > 6mg/dl and creatinine with a cut off value of > 0.3 mg/dl to diagnose PROM were all more than 90%. The sensitivity, specificity, PPV, NPV and accuracy of amniotic fluid index (AFI) to diagnose PROM were 30%, 91.8%, 83.33%, 57.32% and 62 % respectively, with a cut-off value of ≤ 7 cm. The areas under the curves are 0.952 for creatinine, 0.999 for urea and 0.635 for AFI.
Conclusion: Detection of vaginal fluid urea and creatinine to diagnose PROM is a simple, reliable and rapid test. Introduction of this method into routine use even in low resource community setting is feasible, practical and cost effective.