Diagnostic power of the vaginal washing-fluid prolactin assay as an alternative method for the diagnosis of premature rupture of membranes

Abstract

Objective: The purpose of this study was to determine the reliability of the vaginal washing-fluid prolactin assay for the diagnosis of premature rupture of membranes (PROM) and to determine a diagnostic cut-off value.Study design: Seventy pregnant women between 11 and 40 weeks of gestation who were admitted with vaginal fluid leakage were included in the study group, and were then further subdivided into two subgroups according to amniotic fluid pooling and nitrazine paper test results. Group 1 was the ‘confirmed PROM group’, positive for both pooling and nitrazine (38 patients). Group 2 was the ‘suspected but unconfirmed PROM group’ which had possible pooling and/or nitrazine (32 patients). Seventy pregnant women between 11 and 40 weeks of gestation without any complaint and complication were included in the control group (group 3). All patients underwent vaginal washing-fluid sampling and prolactin level determination. For the statistical analysis one-way analysis of variance, Tukey multiple comparison test, χ2test and receiver operating characteristic (ROC) curve analysis were used.Results: Geometric mean values of vaginal washing-fluid prolactin levels were 616.59 µIU/ml for group 1, 23.98 µIU/ml for group 2 and 10 µIU/ml for group 3 (p<0.0001). The optimal diagnostic cut-off value was found to be 30 µIU/ml with 95% sensitivity, 78% specificity, 84% positive predictive value, 93% negative predictive value, 87% accuracy and 11.30 relative risk.Conclusions: We recommend vaginal washing-fluid prolactin level determination as an alternative diagnostic method for PROM.