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

Abstract

Background. To determine whether the measurement of β-human chorionic gonadotropin (β-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 β-HCG levels. Results. The median and range of vaginal fluid β-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 β-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, 39.8mIU/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 β-HCG may be reliable, simple, and rapid test in diagnosing PROM and used as a adjunctive test in equivocal cases. © Acta Obstet Gynecol Scand 2005.