Cervicovaginal HCG and cervical length for prediction of preterm delivery in asymptomatic women at high risk for preterm delivery

Abstract

To predict the risk of preterm birth (<37 weeks) or early preterm birth (<34 weeks) by cervicovaginal HCG and cervical length measured between 24-28 weeks of gestation in asymptomatic women at high risk for preterm birth. This study was conducted in the departments' of Obstetrics & Gynaecology and Immunopathology of the Postgraduate Institute of Medical Education and Research, Chandigarh, India. In 75 pregnant women at high risk for preterm birth because of prior one on more preterm births due to spontaneous labour or ruptured membranes, cervicovaginal HCG and cervical length (by TVS) were measured between 24-28 weeks of gestation. These parameters were correlated individually and in combination for prediction of preterm birth. Of the 75 women, 20 (26.7%) delivered <37 weeks and 6 (8%) delivered <34 weeks. To predict delivery <37 weeks, cervical length <2.95 cm had a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 75%, 80.1%, 71.4% and 90.7% respectively, and cervicovaginal HCG >4.75 mIU/ml had a sensitivity, specificity, PPV, and NPV of 70%, 61.81%, 40% and 85% respectively. To predict delivery <34 weeks, cervical length <2.65 cm had a sensitivity, specificity, PPV, and NPV of 50%, 85.50%, 23.08% and 95.16% respectively; and cervicovaginal HCG >14 mIU/ml had a sensitivity, specificity, PPV and NPV of 83.3%, 85.5%, 33.3% and 98.3% respectively. Cervical length was superior to predict delivery <37 weeks, whereas HCG was superior to predict delivery <34 weeks. Their combination was superior to predict preterm birth both <37 weeks or <34 weeks, than either parameter used alone. In high risk asymptomatic women, increased cervicovaginal HCG and reduced cervical length and between 24 to 28 weeks of gestation increased the risk of preterm delivery.