Cervical Length & Leading Placental Edge to Internal OS Measurements - TA vs TV

Abstract

Brief Description of the Purpose of the StudyTo compare cervical length/leading placental edge from the internal cervical os measurements obtained by both transabdominal (TA) and transvaginal (TV) approach and to assess intra / inter-observer variation for these measurements.MethodsCross sectional study of 374 consecutive pregnancies with gestation 12 weeks to term. The cervical length was estimated as the distance from internal to external os, and the placenta / cervix distance as the leading placental edge to internal cervical os. Bland-Altman plots were used to evaluate the two methods, both overall and stratified by gestation. Test characteristics were calculated for cervix<25mm. On twenty of the above studies, two observers measured each of the parameters at least twice. Intra / inter-observer error was the mean deviation calculated as a percentage of the mean measurement.Main ResultsOverall, TA measurements of both cervix and placental edge position were statistically different from measurements obtained TV. In second trimester, the TA cervix estimate was 2.7 mm < (95% CI 1.8-3.6) TV estimate. >24 weeks gestation, the difference between the two methods for cervix was not statistically significant, however, the TA measurements detected only 1 of 16 cervix < 25 mm with a subsequent sensitivity of 0.06. There was a large inter-observer variation seen for both parameters whilst intra-observer difference was higher for TA placental edge than for the other measurements.Importance of the ConclusionsTA estimates of cervix and placental edge position did not reflect the estimates obtained by TV assessment. As both measures are important markers of pregnancy outcome and management, the transabdominal method in the present form is insufficient in clinical management. Brief Description of the Purpose of the StudyTo compare cervical length/leading placental edge from the internal cervical os measurements obtained by both transabdominal (TA) and transvaginal (TV) approach and to assess intra / inter-observer variation for these measurements. To compare cervical length/leading placental edge from the internal cervical os measurements obtained by both transabdominal (TA) and transvaginal (TV) approach and to assess intra / inter-observer variation for these measurements. MethodsCross sectional study of 374 consecutive pregnancies with gestation 12 weeks to term. The cervical length was estimated as the distance from internal to external os, and the placenta / cervix distance as the leading placental edge to internal cervical os. Bland-Altman plots were used to evaluate the two methods, both overall and stratified by gestation. Test characteristics were calculated for cervix<25mm. On twenty of the above studies, two observers measured each of the parameters at least twice. Intra / inter-observer error was the mean deviation calculated as a percentage of the mean measurement. Cross sectional study of 374 consecutive pregnancies with gestation 12 weeks to term. The cervical length was estimated as the distance from internal to external os, and the placenta / cervix distance as the leading placental edge to internal cervical os. Bland-Altman plots were used to evaluate the two methods, both overall and stratified by gestation. Test characteristics were calculated for cervix<25mm. On twenty of the above studies, two observers measured each of the parameters at least twice. Intra / inter-observer error was the mean deviation calculated as a percentage of the mean measurement. Main ResultsOverall, TA measurements of both cervix and placental edge position were statistically different from measurements obtained TV. In second trimester, the TA cervix estimate was 2.7 mm < (95% CI 1.8-3.6) TV estimate. >24 weeks gestation, the difference between the two methods for cervix was not statistically significant, however, the TA measurements detected only 1 of 16 cervix < 25 mm with a subsequent sensitivity of 0.06. There was a large inter-observer variation seen for both parameters whilst intra-observer difference was higher for TA placental edge than for the other measurements. Overall, TA measurements of both cervix and placental edge position were statistically different from measurements obtained TV. In second trimester, the TA cervix estimate was 2.7 mm < (95% CI 1.8-3.6) TV estimate. >24 weeks gestation, the difference between the two methods for cervix was not statistically significant, however, the TA measurements detected only 1 of 16 cervix < 25 mm with a subsequent sensitivity of 0.06. There was a large inter-observer variation seen for both parameters whilst intra-observer difference was higher for TA placental edge than for the other measurements. Importance of the ConclusionsTA estimates of cervix and placental edge position did not reflect the estimates obtained by TV assessment. As both measures are important markers of pregnancy outcome and management, the transabdominal method in the present form is insufficient in clinical management. TA estimates of cervix and placental edge position did not reflect the estimates obtained by TV assessment. As both measures are important markers of pregnancy outcome and management, the transabdominal method in the present form is insufficient in clinical management.