Mid-trimester cervical consistency index and cervical length to predict spontaneous preterm birth in a high-risk population

Background: Short cervical length (CL) has not been shown to be adequate as a single predictor of spontaneous preterm birth (sPTB) in high-risk pregnancies. Objective: The objective of this study was to evaluate the performance of the mid-trimester cervical consistency index (CCI) to predict sPTB in a cohort of high-risk pregnancies and to compare the results with those obtained with the CL. Study Design: Prospective cohort study including high-risk singleton pregnancies between 19 +0 and 24 +6 weeks. The ratio between the anteroposterior diameter of the uterine cervix at maximum compression and at rest was calculated offline to obtain the CCI. Results: Eighty-two high sPTB risk women were included. CCI (%) was significantly reduced in women who delivered <37 +0 weeks compared with those who delivered at term, while CL was not. The area under the curve (AUC) of the CCI to predict sPTB <37 +0 weeks was 0.73 (95% confidence interval [CI], 0.61-0.85), being 0.51 (95% CI, 0.35-0.67), p = 0.03 for CL. The AUC of the CCI to predict sPTB