OP13.07: Cervical elastography in first and second trimester: assessing cervical remodelling and predicting preterm birth

To explore the utility of cervical elastography in singleton pregnancies in the first and second trimesters to assess cervical remodelling and predict spontaneous preterm birth (sPTB). This prospective study enrolled pregnant women scheduled for first trimester ultrasound scans at our hospital. Cervical elastography was conducted by trained sonographers in both the first trimester (11-14 weeks) and the second trimester (20-24 weeks).Cervical elastographic parameters including cervical length (CL), elasticity contrast index (ECI), hardness ratio (HR), internal os stiffness(IOS), external os stiffness (EOS), and the ratio of IOS and EOS (RATIO) were measured using E-Cervix. A total of 587 pregnant women included in the study, 38 (6.47%) had sPTB at less than 37 weeks of gestation,43 cases (7.3%) had short cervix(CL ≤ 25 mm) in the second trimester. CL and HR were significantly lower in the second trimester compared to the first trimester, while ECI, IOS and RATIO were significantly higher(P < 0.001).The parameters in the first trimester showed no significant differences between the term and preterm birth groups (P > 0.05).In the second trimester, ECI was significantly higher and CL was significantly lower in the preterm birth group VS term birth group (P < 0.05). In the first trimester, ECI was significantly higher in the short cervix group, while HR and CL were significantly lower (P < 0.05) VS the normal group. The AUC for predicting preterm birth was 0.617 for CL, 0.603 for ECI alone, and 0.654 for the combination of ECI and CL. The AUC for predicting short cervix was 0.679 for CL alone and 0.703 for the combination of ECI and HR. Cervical Elastography can be used to visualise morphological and histological changes in the cervical remodelling. Combining CL with ECI in the second trimester can be used to predict the risk of sPTB. Although elastography parameters in the first pregnancy may not predict the risk of sPTB, combining CL with ECI and HR can be utilised to predict the risk of a short cervix.