Vaginal fluid β‐human chorionic gonadotropin level in the diagnosis of premature rupture of membranes

BACKGROUND: To determine whether the measurement of beta-human chorionic gonadotropin (beta-HCG) level in the vaginal washing fluid could be useful for the diagnosis of premature rupture of membranes. METHODS: Totally, 120 pregnant women were enrolled in this study. Subjects were divided into four groups [group I, no preterm labor and term delivery (n = 38); group II, preterm labor and term delivery (n = 12); group III, preterm labor and consequent premature delivery (n = 24); group IV, preterm labor with premature rupture of membranes (PROM) and consequent premature delivery (n = 46)]. After irrigating the posterior vaginal fornix with 3 ml of sterile saline and the obtained vaginal washing fluid, we measured beta-HCG levels. RESULTS: The median and range of vaginal fluid beta-HCG levels were 3.60 (0.09-30.52), 4.42 (0.33-10.02), 15.50 (0.25-378.62), and 512.53 (26.95-3507.20) mIU/ml in group I, group II, group III, and group IV, respectively. Vaginal beta-HCG level was significantly higher in patients with PROM followed by premature delivery (group IV) than patients in other groups (P < 0.01). From the receiver operating characteristic curve, 39.8 mIU/ml was set as a cutoff value. Sensitivity, specificity, positive predictive value, and negative predictive value were 95.5, 94.7, 91.3, and 97.3%, respectively. CONCLUSION: Our study demonstrated that the measurement of vaginal fluid beta-HCG may be reliable, simple, and rapid test in diagnosing PROM and used as a adjunctive test in equivocal cases.