Comparative analysis of three ultrasonic methods for the cervical length in predicting the preterm birth

Abstract

Objective To compare three ultrasonic methods of transabdominal , transvaginal , and transperineal ultrasonogra-phy for the cervical length （ CL） in predicting the preterm birth .Methods The pregnancy women with threatened preterm labor in Hunan Provincial Hospital of Maternal and Child Health from January , 2012 to December, 2013 were chosen to measure the cervical length by sonography , and were randomly divided into three guoups （ 280 pregnancy women in each group ） , including Group Ⅰ（ transabdominal ） , groupⅡ（ transvaginal ） , and group Ⅲ （ transperineal ） .The cervical length and the pregnancy outcome were fol-lowed up.Results The acceptance rate of group Ⅱ（81.8%=229/280） was significantly lower than that of groupⅠ（100%=280/280）and group Ⅲ（99.3%=278/280）（ P <0.05）.The realization ratio of the cervix in group Ⅰ（85.0%=238/280） was signifi-cantly lower than that of group Ⅱ（98.7%=226/229） and group Ⅲ （98.2%=273/278） （ P <0.05）.The preterm birth rate of 48.6%（18/37） in groupⅠ, 37.8%（28/74） in groupⅡ, and 37.1%（33/89） in groupⅢin the pregnancy women with CL <3 cm was significantly higher than the corresponding preterm birth rate of 17.9%（36/201） in groupⅠ, 13.2%（20/152）in groupⅡ, and 13.6% （25/184） in groupⅢin the pregnancy women with CL≥3 cm.The sensitivity of groupⅠ（33.3%=18/54） was significantly lower than that of group Ⅱ（58.3%=28/48） and group Ⅲ（56.9%=33/58）.Conclusions The cervical length measured by ultra-sound is valuable in predicting preterm birth among the pregnancy women with threatened preterm birth .The transperineal ultrasonogra-phy is superior to transabdominal and transvaginal ultrasonography in predicting preterm birth , and is worth being popularized . Key words: Cervix uteri/ultrasonography; Cervical length measurement; Premature birth; Forecasting