OP09.03: Cervical elastography in predicting spontaneous preterm delivery in women with singleton pregnancy having cervical length > 25 mm at mid‐trimester

Predicting spontaneous preterm delivery (sPTD) using cervical elastography in women with short cervix has been previously reported, however, not in pregnancy with normal cervical length (CL). Therefore, we sought to assess the role of cervical elastography in sPTD in women with CL > 25 mm at mid-timester. Multicentre prospective study was performed between June 2018 to December 2020 by the Korean Research Group of Cervical Elastography (grant ID: HI18C1696). Asymptomatic singleton pregnancies who underwent ultrasound between 16+0 and 23+6 weeks of gestation and having CL > 25 mm were extracted for analysis. Cervical elastography were performed using E-cervixTM (WS80A and HERA, Samsung Medison). Elastographic parameters assessed were IOS strain, EOS strain, ECI, strain mean (SM), hardness ratio. sPTD was defined as delivery < 37 weeks of gestation due to either spontaneous preterm labour or rupture of membranes. Elastographic parameters were compared between pregnancies with and without sPTD. Predictive values for sPTD were analysed by the area under the ROC curve (AUC). Of the 1481 women, 852 nulliparous women and 629 multiparous women were included. 65 (4.4%) had sPTD. IOS and SM were significantly associated with an increased risk of sPTD (OR 1.43 and 1.59). In the subgroup analysis, there was no significant difference for all elastographic parameters between the nulliparous women with and without sPTD. In contrast, higher IOS, EOS and SM were associated with an increased risk of sPTD in multiparous women (adjusted for CL and prior PTD; p < 0.001, 0.007 and 0.002, respectively). ROC analysis of IOS for prediction of sPTD in multiparous women showed an AUC of 0.692 (p < 0.001). The combination of CL, prior PTD and IOS increased the AUC to 0.733 compared with IOS alone (p < 0.001). The cervical elastography at mid-trimester may be useful method for prediction of sPTD in multiparous women with CL > 25 mm. A combination of IOS and clinical factors appears to improve the predictability of sPTD.