A study of association of cervical length at 18 weeks and 23 weeks gestation in predicting preterm delivery in twin pregnancies
Shilpa Bajpai, Devendra Arora, Sushil Chawla
Background: Twin pregnancy complicates 1.4% of all pregnancies but accounts for 15% of neonatal mortality. The ability to predict preterm delivery could allow targeted intervention such as antenatal steroid induction, cervical encerclage and tocolysis, which might improve neonatal outcome. The length of cervix may be useful in predicting the risk of premature delivery, with a shorter cervix predicting a higher risk. Objectives: The present study was undertaken to evaluate the cervical length during 18th and 23rd week period of gestation in twin pregnancy for predicting preterm delivery and also find the correlation between cervical length and occurrence of preterm birth. Method: In this prospective observational study, a total of 69 antenatal patients underwent cervical length screening at 18 weeks and 23 weeks period of gestation at a tertiary level teaching hospital were recruited. 17 women did not deliver at the study site and were lost to follow up. 3 patients have been excluded from the study as they have been electively terminated because of obstetrical reasons. Results: 22.4% women at 18 weeks period of gestation and 42.9% women at 23 weeks period of gestation with cervical length <25mm delivered preterm, making the relationship of short cervix to preterm delivery statistically significant (P value< 0.001). Sensitivity was 18.92% at 18 weeks and sensitivity was 54.05% at 23 weeks period of gestation while specificity and positive predictive value (PPV) was 100% at 18 week and 23 weeks period of gestation. Conclusion: The present study shows that there is fair amount of negative correlation between cervical length and the occurrence of pre-term birth. Which means that as the cervical length increases the chance of preterm birth decreases. Shorter the cervix greater is the likelihood of preterm delivery.