P01.02: The detection rates of shear wave speed in various uterine cervical regions during pregnancy and their determinant factors

Abstract

Objectives:To evaluate the discrepancies between transabdominal and transvaginal sonographic measurements of the cervix in singleton and twin pregnancies and to assess whether maternal weight influences these discrepancies. Methods: A prospective cohort study. Transabdominal and transvaginal cervical lengths measurements were obtained before and after voiding (respectively) in pregnant women between 14 and 25 weeks of gestation. Measurements were compared between singleton and twin pregnancies and correlated with maternal age, and BMI. Statistical analysis was performed in order to determine a transabdominal cervical length cut-off with 100% confidence for transvaginal cervical length above 30mm. Results: 52 pairs of twin pregnancies and 388 singleton pregnancies were included. The mean cervical length measured abdominally for twin and singleton pregnancies was 35.6 ± 5.3mm and 36.8 ± 6.9mm respectively. The mean cervical length measured vaginally was 40.3 ± 6.6mm and 42.2 ± 7.2mm. The average discrepancy between the two methods was 4.7mm in twin pregnancies and 5.4mm in singleton. Abdominal cervix measurements correlated with vaginal measurements and were consistently shorter. The discrepancy between abdominal and vaginal measurements did not correlate with singleton or twin pregnancies, maternal body mass index or maternal age. All women with abdominal cervical length >35mm had a corresponding vaginal cervical length >30mm. Conclusions: The use of abdominal measurement of cervical length could be an effective initial tool for cervical length screening in both singleton and twin pregnancies. Cervical length of >35mm could be used as a cut-off value that might make the vaginal measurement redundant in some cases. P01.02The detection rates of shear wave speed in various uterine cervical regions during pregnancy and their determinant factorsObstetrics and Gynecology, Kurume University, Kurume, Fukuoka, Japan Objectives: To analyse detection rates of shear wave speed (SWS) -a quantitative parameter of tissue stiffness, in various cervical regions during pregnancy and their determinant factors. Methods: Subjects were 196 cases of normal singleton pregnancy at 14-37 weeks' gestation, cared for in our hospital between October 2016 and February 2017. SWS of the cervix was measured using transvaginal ultrasound equipment (Aplio 500, Toshiba). Samplings were taken at 14-17, 18-21, 22-25, 26-29, 30-33, 34-37 weeks from the anterior (A), cervical canal (C) and posterior (P) on sagittal sections of the cervix in the external and internal os (EO/IO) regions. On a colour-coded elastogram, the SWS of a circular region of interest (ROI) with a 5 mm diameter was used to calculate the mean and standard deviation. The measurement was considered adequate when total colour-staining in a circular ROI and/or the coefficient of variation of the SWS<30%. For each age-group, rates for detecting adequate measurements were compared between sampling points. Factors related to adequate measurement: circular ROI depth and the angle in degree...