Prediction of spontaneous preterm birth by cervical length changes in twin pregnancies
- Author:
Xi-fang ZUO
1
;
Yu-feng DU
;
Zi-yi CHENG
;
Jing YANG
;
Shan LU
;
Chun TONG
;
Hai-hui MA
1
;
Yuan WEI
;
Yang-yu ZHAO
Author Information
- Publication Type:Journal Article
- Keywords: twins; cervical length; preterm birth; transvaginal ultrasound; prediction
- From: Chinese Journal of Practical Gynecology and Obstetrics 2019;35(09):1019-1022
- CountryChina
- Language:Chinese
- Abstract: OBJECTIVE: To investigate the predictive value of cervical length（CL）changes in spontaneous preterm birth（SPTB）in twin pregnancies in the second and third trimesters of pregnancy.METHODS: A retrospective analysis was made of 166 cases of twin pregnant women who underwent transvaginal ultrasound to measure CL during the second trimester of pregnancy（20~25 weeks）and the third trimester of pregnancy（28~32 weeks）from January 2014 to December 2017 in the Third Hospital of Peking University and Tongzhou Maternal and Child Health Hospital of Beijing.Evaluate the predictive value of CL changes in SPTB before 32 and 34 weeks.The area under the receiver-operating characteristics（ROC）curve was compared by bootstrap method.Assessment of the value of CL in the third trimester of pregnancy and CL in the second trimester of pregnancy alone in predicting SPTB before 32 and 34 weeks.RESULTS: Of the 166 cases,90 were full-term delivery and 76 were premature delivery.The median CL of mid and late pregnancy was 34 mm and 29 mm respectively,and it was 35.5 mm and 31 mm,and in full-term delivery.32.5 mm and21 mm in premature delivery,respectively.There were significant differences among the three groups（All P<0.001）.According to whether the shortening of CL was more than 20%,they are divided into shortening group（CL shortening more than 20%,78 cases）and stabilizing group（no shortening of CL or shortening less than 20%,88 cases）.The preterm birth rate of shortening group was 2.22 times and 1.85 times higher than that of stabilizing group before 32 weeks and 34 weeks,but there was no significant difference.Of 40 cases with CL≤ 25 mm,there were 34 cases in shortening group,6 cases in stabilizing group.Excluding these twin pregnant women,the preterm birth rate in the shortening group increased by 7.58 times and 2.09 times than that in the stabilizing group before 32 weeks and 34 weeks.There was a significant difference in the preterm birth rate between the shortening group and the stabilizing group before 32 weeks（P=0.049）.The area under ROC curve of preterm birth predicted by CL in late pregnancy was increased compared with that in mid-pregnancy before 32 weeks and 34 weeks,but the difference was not statistically significant.CONCLUSION: In twin pregnancies,the CL shortening ≥ 20% at 28~32 weeks of gestation increases the risk of preterm birth before 32 weeks;with CL>25 mm and CL shortening≥ 20%,it can better predict preterm birth before 32 weeks.
