Application Of Transperineal Ultrasound Measurement Of Anterior Uterocervical Angle And Cervical Length In Predicting Preterm Delivery

Objective To study the value of anterior uterocervical angle and cervical length in predicting preterm labor after 28 weeks of pregnancy.Methods From May 2018 to May 2019,253 pregnant women with clinical symptoms of threatened preterm labor or high risk factors of preterm labor in singlebirth primipara were selected.253 pregnant women who underwent prenatal examination are from 28+ weeks of gestations.The cervical length and anterior uterocervical angle were measured by transperineal ultrasound three times.Draw the ROC curve and calculate the area under the curve.In the case of cervical funnel formation,the length of funnel was measured and the cervical index was calculated.Follow-up and accurate record of each pregnant woman delivery weeks of pregnancy.Results There were 253 cases,199 full term,54 preterm,the rate of preterm delivery was 21.3%.The average length of cervix was26.18±4.33 mm in preterm labor group and 31.36±3.33 mm in term labor group(p<0.05).The mean anterior uterocervical angle was(117.50±9.60)°in preterm labor group and(102.35±7.59)° in term labor group(p<0.05).Draw the ROC curve and calculate the area under the curve.The best critical value of cervical length was 25.5 mm,and the best critical value of anterior uterocervical angle was 115.5°.The critical value of cervical length predicted the incidence of premature delivery in 51.8%,and the critical value of anterior uterocervical angle predicted the incidence of premature delivery in 83.3 %.The sensitivity and specificity of the critical value of cervical length were 51.8% and 51.9%,respectively the positive predictive value was 82.3%,the negative predictive value was 88.1%.The sensitivity and specificity of the critical value of anterior uterocervical angle were 83.3% and 95.5%,respectively the positive predictive value was 83.3%,the negative predictive value was 95.4%.Among the 253 cases,14 cases of cervical funnel formed in pregnant women,of which 9 cases were premature delivery.The rate of preterm delivery was 88.9% in 9 women with cervical index ?0.5.The rate of preterm delivery was 20.0% in 5 women with cervical index<0.5(p < 0.05).Conclusion The measurement of anterior uterocervical angle and cervical length by transperineal ultrasound has a certain clinical value in predicting preterm birth,and is worthy of clinical application and promotion.