Cervical sonoelastography for improving prediction of preterm birth compared with cervical length measurement and fetal fibronectin test

Aim: Accurate prediction of the risk of spontaneous preterm birth is crucial for the clinical management of patients with preterm labor. The aim of the study was to investigate whether cervical sonoelastography improves prediction of spontaneous preterm birth compared with cervical length measurement and a fetal fibronectin (fFN) test. Methods: A prospective cohort study was conducted including 64 patients with preterm labor at 23-34 weeks of gestation. Patients had an fFN test and transvaginal cervical length measurement, followed by real-time cervical sonoelastography. The ratio of nondeformable tissue to the total area of a designed region of interest was analyzed and related to the gestational week of delivery. Results: Cervical sonoelastography and fFN test show a significant correlation with spontaneous preterm delivery (P = 0.007, P = 0.001), resulting in 72.7%/ 36% sensitivity and 73%/ 95% specificity. The positive predictive value (PPV) was 61.5%/81.8% and the negative predictive value was 81.8%/70%. The cervical length was not different in cases with and without term delivery (P = 0.165). Conclusions: Cervical sonoelastography is a promising technique that can complement routine diagnostic procedures to improve prediction of preterm birth. The PPV is improved by an fFN test.