Diagnostic power of quantitative HCG in cervico-vaginal washings in women with premature rupture of membranes

Premature rupture of membranes (PROM), occurs in 2-25% of pregnant women. Traditionally, clinical and laboratory tests utilized for the diagnosis of PROM are fraught with both false positive and false negative results caused by various factors that result in an equivocal or delayed diagnosis. The absence of a non-invasive 'gold standard' for the diagnosis of PROM has led to the search for alternative biochemical markers. This research has been conducted to compare the diagnostic power of qualitative and quantitative HCG of cervicovaginal washings for the diagnosis of PROM.s

This Diagnostic-Experimental study was undertaken with cervico-vaginal samples collected from singleton pregnancies between 14-41 weeks of gestation. Totally 86 pregnant women referred to Vali-Asr Hospital, Zanjan, in 2006, were enrolled in this study. Subjects were divided in two groups: 43 subjects with confirmed PROM (amniotic fluid pooling (+), nitrazine paper test (+), and fern test (+)), and 43 women in the control group (amniotic fluid pooling (-), nitrazine paper test (–), and fern test (-)). Washings were then collected from the posterior vaginal fornix with the use of 5 ml of sterile saline irrigation and aspiration techniques. We measured HCG levels with the ELISA test.

The median HCG levels were 250.60 (mIU/mL) and 6.2 (mIU/mL) in PROM and control group respectively. With, 22 (mIU/mL) set as a cutoff value on the receiving operating characteristic curve, (ROC), sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 95.3, 97.7, 97.6, 95.5 and 96%, respectively.

Quantitative HCG measurement of cervico-vaginal washings was an accurate test for the diagnosis of PROM in our study.