Cervical strain values measured by ultrasonographic elastography in pregnant women between 18 and 40 weeks’ gestation

Objective: To evaluate the reproducibility, examine the cervical tissue strain using sonographic elastography, and investigate the factors affecting the cervical tissue strain in pregnant women. Material and Method: A cross-sectional study of 116 pregnant women at 18 to 40 weeks of gestation between September 1, 2014 and January 31, 2015 was done. Transvaginal manual compression elastographic examinations of the uterine cervices were performed in three planes, one mid-sagittal, and two cross-sectional planes at the level of internal os and external os. The intra-observer and inter-observer reliabilities were evaluated. The mean cervical strain values in the seven gestational age groups and four cervical length group were examined. Finally, the associations between cervical strain values and maternal age, maternal BMI, parity, gestational age, and cervical length were investigated. Results: Intra-observer and inter-observer reliabilities were highest at proximal portion of anterior lip in sagittal plane and endocervical canal of internal os in cross-sectional plane. Cervical length had moderate negative correlation with gestational age and cervical strain values while cervical strain values had moderate positive correlation with gestational age. Conclusion: Cervical elastography has good intra-observer and inter-observer reliabilities. The cervical strain values at proximal portion of anterior lip in sagittal plane and endocervical canal of internal os in cross-sectional plane have positive correlation with gestational age and negative correlation with cervical length.