Razi Journal of Medical Sciences

Background: Premature Rupture Of Membranes (PROM) is one of the most important problems of pregnancy and accurate diagnosis of suspicious cases is under special concern. In this regard, researches are being conducted in order to find a reliable, fast and simple method for accurate diagnosis. The purpose of the present study is to evaluate vaginal fluid β-HCG for diagnosis of PROM.

Methods: An observational cross sectional study was performed on 123 pregnant women who were in the third trimester of gestation (gestational age more than 28 weeks of pregnancy). The patients were considered in 3 groups including:  PROM group (41 cases), suspicious for PROM (42 cases) and intact membranes (40 cases). Five ml sterile normal saline was introduced in  to the posterior fornix of vagina,   then vaginal  fluid was aspirated and sent to the laboratory for β-HCG measurement. Finally, the amount of β-HCG was compared in the 3 groups. For data analysis student t-test, One way Anova and Kruskal Walis tests were used. SPSS V.11.5 was also used.

Results: β-HCG concentration was 7.71±15.7 mIU/ml in the intact membrane group, 468.06±366.34 mIU/ml in the PROM group and 176.43± 316.37 mIU/ml in the suspicious group which showed a significant difference between the 3 groups (p=0.000). In order to find an optimal Cut off value for β-HCG, Receiver Operating Characteristics Curve (ROC) was used and a Cut off value of 79.5 mIU/ml with a sensitivity of 95% and specificity of 84% was determined to be optional.

Conclusion: β-HCG is higher in PROM and suspicious for PROM patients, and thus may be used as a suitable, fast and reliable test for detecting PROM.