Ultrasonographic Evaluation of Cervical Length, Cervical Volume and Cervical Vascularization between 18 and 40 Weeks of Gestation

Abstract

Objective: To evaluate the correlation of cervical length, cervical volume and cervical vascularization during pregnancyusing 3D power Dopplerultrasonography, andtoexamine the reliability of these measurements. Methods: This isacross-sectional studyof196pregnant women whodeliveredat term andhadundergonetrans- vaginal3D power Dopplerultrasonographicexaminationof thecervixoncebetween18and40 weeks’gestation. Cervical length,cervicalvolume,vascularizationindex(VI), flow index(FI)andvascularization flow index(VFI) were measured andcalculated. The reliabilityof the measurements was also evaluated. Results: Mean cervical length and volume were 35.2 mm. and 28.2 cm3 . Mean cervical VI, FI and VFI were 2.65,38.44and1.07, respectively. Cervical lengthandcervicalvolumesignificantlydecreasedduringpregnancy (Spearman’s rank correlation coefficient, Rho = -0.422 and -0.514, respectively, correlation significant <0.01). There was a minimal change inthevascular flow indicesbetween18and40 weeks’gestation(Spearman’s rank correlation coefficient, Rho, varied from 0.010 to 0.042). Both intraobserver and interobserver agreement for cervical volume measurements were excellent with intraclass correlation coefficient (ICC) values of 0.96, and 0.95respectively. Intraobserverandinterobserveragreement forvascular flow indices measurements weregood. Conclusion: Cervical length and volume significantly decreased with gestational age. Cervical vascularization tends to be increased,but without statistical significance. The measurements were reliable.

Keywords

• 3D power Doppler transvaginal ultrasonography in pregnancy; cervical length; cervical volume; cervicalvascularization; reliability