Diagnosis of premature rupture of membranes by assessment of urea and creatinine in vaginal washing fluid

Background: Rupture of fetal membranes can occur at any gestational age. Premature rupture of membranes (PROM) means rupture of fetal membranes beforethe onset of labor. Objective: The purpose of this study was to evaluate and compare the reliability of the vaginal washing fluid urea and creatinine for the diagnosis of PROM and todetermine cut-off values. Materials and Methods: A total of 179 pregnant women were recruited. Allpatients underwent different examinations. These included nitrazine paper test, fern test, amniotic fluid pooling, vaginal washing fluid urea and creatinine sampling. Theone group consisted of 126 pregnant women between 14 and 41 weeks of gestation with the complaint of vaginal fluid leakage. Patients who had positive pooling,nitrazine paper test and fern test were considered as confirmed PROM group (group 1). On the other side, patients with pooling (-) and/or nitrazine paper test (-) and/orfern test (-) were taken as suspected unconfirmed PROM cases (group 2). Thecontrol group consisted of 53 pregnant women between 14 and 41 weeks of gestation without any complaint or complication. Weconducted one-way ANOVAtest on the urea and creatinine measures and post-hoc comparison test. Cut-off value was determined by receiver operating characteristic (ROC) curve.Results: Vaginal fluid concentrations of urea and creatinine were significantly different between the three groups (p<0.001). The sensitivity, specificity, positiveand negative predictive values and accuracy were all 100% in detecting premature rupture of membranes by evaluation of vaginal fluid creatinine concentration with a cut-off value of 0.45 mg/dl, respectively. Conclusion: This study demonstrates that of two markers investigated creatinine has the higher diagnostic power.

Keywords:

Premature rupture of membranes , Creatinine , Urea , Vaginal washing fluid