The value of measurement of vaginal fluid creatinine and beta-human chorionic gonadotropin in the diagnosis of premature rupture of membranes

Objective: The purpose of the present study is to evaluate β-human chorionic go- nadotropin (β-hCG) and creatinine levels in the vaginal fluid regarding to diagnosis of premature rupture of membranes (PROM). Material and Methods: This study was conducted on 150 pregnant women in the third trimester (28–40 weeks). The patients were grouped as: (1) PPROM group (75 cases) and (2) intact membranes as control group (75 cases). Three milliliters of ster- ile normal saline were inserted into the posterior fornix of the vagina and then vaginal fluid was aspirated. Creatinine and β-hCG levels in the vaginal fluid were measured β-hCG and creatinine levels were compared between the two groups. Results: The mean vaginal fluid level in Groups 1 and 2 was 0.60±0.72 (0.37) and 0.22±0.11 (0.2) for creatinine and β-hCG which was positive in 411.69±605.65 (146) and 12.71±24.63 (3.9), respectively. There was a statistically significant difference regarding to mean creatinine and β-hCG levels between two groups (p<0.001). Sen- sitivity, specificity, positive predictive value, negative predictive value, and accuracy were all 66.67%, 96%, 94.3%, 74.3%, and 81.3% for creatinine and 94.6%, 82.6%, 84.52%, 93.94%, and 88.67% for β-hCG in detecting PROM with a cutoff value of 0.21 mg/dl for creatinine and 16 mIU/ml for β-hCG. Conclusion: Measuring of β-hCG level in vaginal fluid is accurate, cheap, and simple methods in the diagnosis of PROM. Furthermore, measuring of creatinine level is a simple and accurate method with a lower sensitivity and accuracy than for β-hCG.