Objective: The purpose of this study was to evaluate the reliability of vaginal washing fluid creatinine level for the diagnosis of premature rupture of membranes (PROM).
Method: A prospective diagnostic study performed in Shahid Sedoughi Hospital on 160 pregnant women (30 definite PROM, 30 no PROM and 100 suspected PROM) at 28-40 weeks of gestation. The vagina was washed by injection with a syringe filled with 3 ml of saline solution, and the washing fluid was collected from the posterior vaginal fornix and send to laboratory. Creatinine values in vaginal washing were measured and compared.
Result: The mean vaginal fluid creatinine levels in definite PROM group, suspected PROM and no PROM were 0.40 ± 0.20, 0.16 ± 0.04 and 0.08 ± 0.01 mg/dl, respectively, where the difference was statistically significant (P = 0.001). The sensitivity, specificity, positive and negative predictivity values and accuracy were 98.7, 100, 100, 98.8 and 87.1%, respectively, in detecting PROM by evaluation of vaginal fluid creatinine concentration with cut-off value of 0.14 mg/dl.
Conclusion: This study showed that creatinine determination in vaginal washing fluid is a useful marker for PROM diagnosis. It is a reliable, simple, cheap and rapid test.