Cervical sliding sign at second trimester in the prediction of early preterm birth in twin pregnancy.

OBJECTIVE

To examine the cervical sliding sign (CSS) alongside cervical length (CL) in twin pregnancies to predict preterm birth (PB).

METHODS

Twin pregnancies (n = 37) with no known risk factor for PB were included in this prospective study. CSS was defined as the ultrasonographic finding in which the anterior lip of the cervix slides over the posterior lip with gentle and continuous pressure application. The CSS and CL measurements were held in the second trimester. Early PB was defined as the birth of the fetus before 32 weeks of gestation. The patients were divided into two groups as CSS-positive and CSS-negative.

RESULTS

Whereas 11 (29.7%) of the twin pregnancies were CSS-positive, 26 (70.3%) were CSS-negative. CSS positivity had a sensitivity of 75.0%, a specificity of 82.2%, a positive predictive value of 54.5%, and a negative predictive value of 92.3% to predict early PB. Multivariate logistic regression analysis revealed that CSS positivity was the only significant independent factor related to early PB.

CONCLUSION

CSS was shown to be superior to CL in providing a better insight to predict early PB. CSS evaluation should be performed in twin pregnancies.