Application value of ultrasound elastography for screening of early pregnancy cervical insufficiency: a retrospective case-control study.

Abstract

Objective: This study aimed to investigate changes in the cervical strain rate (SR), cervical length (CL), and uterine artery blood flow parameters during early pregnancy in women with cervical insufficiency and evaluate the clinical efficacy of these markers for screening of cervical insufficiency in early pregnancy.

Methods: This retrospective study in 60 pregnant women with cervical insufficiency and 100 normal pregnant women was conducted between September 2021 and January 2023 and measured ultrasound parameters of the cervix during early pregnancy. The cervical SR, CL, and uterine artery resistance index (RI) were measured in both groups at 11-14 weeks of gestation. Strain elastography represented by the SR was used to assess the hardness of the internal and external cervical openings.

Results: During early pregnancy, the SR at the internal and external cervical openings were significantly higher in the cervical insufficiency group than those in the normal pregnancy group (SR _I: 0.19 ± 0.018% vs. 0.16 ± 0.014%; SR _E: 0.26 ± 0.028% vs. 0.24 ± 0.025%; p < .001). The CL was significantly shorter in the cervical insufficiency group than that measured in the normal pregnancy group (34.3 ± 2.9 mm vs. 35.2 ± 1.99 mm; p = .036), while cervical blood perfusion was also poorer in the cervical insufficiency group than that in the normal pregnancy group (uterine artery RI: 0.76 ± 0.07 vs. 0.74 ± 0.05; p = .048). Receiver operating characteristic (ROC) curve analysis showed that the optimal critical values for diagnosing cervical insufficiency were 0.17% for SR _I, 0.25% for SR _E, 33.8 mm for CL, and 0.78 for uterine artery RI. Of these parameters, the ROC curve for SR _I had the largest area under the curve [AUC = 0.89 (p < .001)], with the highest sensitivity (78%) and specificity (82%). Multivariate logistic regression analysis demonstrated that the SR at the internal cervical opening (OR 17.47, 95% confidence interval (CI) 5.08-60.08; p < .001) and CL (OR 5.05, 95% CI 1.66-15.32; p = .004) still showed significant differences between the two groups.

Conclusion: Cervical elastography is an effective tool for screening early pregnancy cervical insufficiency. The SR at the internal cervical opening is a valuable indicator for screening cervical insufficiency and has superior clinical efficacy for screening for this condition compared to that of CL and the uterine artery blood flow index.