Diagnostic Efficacy of Cervical Elastography in Predicting Spontaneous Preterm Birth in Pregnancies with Threatened Preterm Labor

Abstract

Background/Objective: Accurately identifying women at high risk for preterm birth among those with threatened preterm labor (PTL) is crucial for effective interventions or tocolytic management to reduce preterm birth and its complications. This study aimed to determine the predictive value of cervical elastography for preterm delivery before 37 weeks of gestation in patients with threatened PTL and a cervical length greater than 15 mm. Methods: This prospective cohort study included pregnant women presenting with threatened PTL at between 24 and 34 weeks gestation. All participants underwent cervical elastography at diagnosis. We compared cervical elastography parameters between women who delivered spontaneously preterm (<37 weeks) and those who delivered at full term and assessed the ability of these parameters to predict spontaneous preterm delivery. Results: Among the 107 enrolled individuals with threatened PTL and a cervical length of >= 15 mm, 55 (42%) experienced preterm birth (<37 weeks). Internal os stiffness (IOS), internal-to-external os stiffness ratio (IOS/EOS ratio), and elasticity contrast index (ECI) were significantly associated with a risk of preterm birth compared to full-term birth. The IOS/EOS ratio was associated with 10-fold higher odds of preterm birth at <37 weeks (95% confidence interval [CI], 1.82-59.98), and ECI was associated with 1.5-fold higher odds (95% CI, 1.01-2.37). The IOS/EOS ratio demonstrated good predictive value (area under the curve (AUC) = 0.678) and the combination of CL <= 25 mm and the IOS/EOS ratio had good diagnostic performance for predicting preterm birth (AUC = 0.708). Conclusions: Cervical elastography using the E-Cervix (TM) system appears to improve the ability to predict preterm birth in pregnant women with threatened PTL and a cervical length greater than 15 mm.