Human chorionic gonadotropin in cervicovaginal secretions as a predictor of preterm birth.

OBJECTIVE

To compare the qualitative (QL) and quantitative (QN) levels of betahCG in cervicovaginal secretions as predictors of preterm birth.

METHODS

The study included 100 women. QL and QN assays were done with velocit kit and ELISA, respectively.

RESULTS

A positive QL assay had sensitivity of 78%, specificity 95%, positive predictive value (PPV) 90%, negative predictive value (NPV) 88% and odds ratio (OR) = 70.87 (95% CI = 18.50, 271.50). The likelihood ratios (LRs) for positive and negative tests were 15.6 and 0.06, respectively. Using a cutoff value of 34.5 mIU/ml, the QN assay had sensitivity of 86%, specificity 86%, PPV 78% and NPV 92%, OR = 36.90 (95% CI = 10.79, 126.15). The LRs for positive and negative tests were 6.14 and 0.16, respectively.

CONCLUSION

The simple and cheaper QL betahCG test is a better predictor of preterm birth as compared to the QN test.