Cervical length and cervicovaginal HCG for prediction of pre-term birth in women with signs and symptoms of pre-term labour.

The study group consisted of 100 women with a singleton pregnancy with pre-term labour between 26-36 weeks' gestation. Cervicovaginal secretions were collected for HCG assay and cervical length was measured by transvaginal sonography (TVS). These parameters were analysed to predict pre-term birth. The pre-term delivery rate was 55%; 24% delivered within 48 h and 11% within 7 days of admission. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of cervical length <or=2.5 cm to predict delivery within 48 h and 7 days of admission were 62.5%, 89.5%, 65.2%, 88.3% and 60.0%, 96.9%, 91.3%, 81.8% respectively; and those of qualitative HCG were 87.5%, 80.3%, 58.3%, 95.3% and 77.1%, 86.2%, 75%, 87.5% respectively. HCG value of >or=45 mIU/ml was the optimal cut-off, with a sensitivity, specificity, PPV and NPV for predicting delivery within 48 h and 7 days to be 95.8%, 73.7%, 53.5% and 98.2% and 85.7%, 80%, 69.8% and 91.2%, respectively. Combining either qualitative or quantitative HCG assay with cervical length significantly increased the sensitivity and NPV of cervical length alone for prediction of pre-term delivery both within 48 h and 7 days. It was concluded that increased cervicovaginal HCG and reduced cervical length predicted an increased risk of pre-term delivery in women with pre-term labour. Qualitative cervicovaginal HCG assay may be used as a bedside test to predict pre-term delivery within 48 h or within 7 days.