955: Novel application assessing cervical stiffness in second trimester

Abstract

Cervical elastography is a novel, non-invasive assessment of tissue stiffness by transvaginal ultrasound (TVUS). which may be useful in the prediction of preterm birth. Our objective is to establish normative data of cervical elastography indices by second trimester TVUS. This is an IRB approved prospective cohort study utilizing Samsung’s E-cervix application. All patients presenting for routine cervical length (CL) by TVUS at a single academic perinatal ultrasound unit from March-July 2019 were included. Women who had a cerclage in place, or prior cervical excision procedures were excluded. The areas of the internal and external os were identified and marked with a machine defined 1 cm semi-circle and the following parameters calculated by the application (Figure 1): Internal Os Stiffness (IOS), External Os Stiffness (EOS), and Hardness Ratio (HR). Stiffness increases as the value approaches 0 and is softer as it approaches 1. Hardness Ratio (HR) is defined as % of total cervical area characterized as hard (i.e. red pixel). Measurements were obtained by RDMS certified sonographers. The average of three measurements were used for analysis and the intra-class correlation was assessed. Pearson correlation coefficients were used to determine the association between each of the E-cervix parameters and cervical length. 619 patients met criteria for analysis with a median maternal age of 32 (18-49) years. 54% were white. Median gestational age at assessment was 20 (15-29) weeks. 96% were singleton pregnancies. Prior preterm birth rate was 9.7%. All measurements except EOS had good to excellent intra-observer reliability. Normative data is provided in Table 1 with median Hardness Ratio 66.83, Internal Os Stiffness 0.24, External Os Stiffness 0.31, IOS/EOS 0.81, and CL 37.3 mm. Cervical elastography was found to be an easy and reliable tool for the evaluation of novel cervical parameters in the second trimester. Furthermore, these findings suggest cervical stiffness (function) does not correlate with CL (structure), and maybe an important assessment for preterm birth.View Large Image Figure ViewerDownload Hi-res image Download (PPT)