经阴道超声测量瘢痕子宫再次妊娠早期子宫肌层厚度对胎盘植入的预测价值

The predictive value of transvaginal ultrasound measurement of myometrium thickness in the first trimester of second pregnancy in scarred uterus for placenta accreta spectrum

目的分析经阴道超声测量瘢痕子宫再次妊娠早期子宫肌层厚度对胎盘植入(PAS)的预测价值。方法选择2020年9月至2021年9月于海南现代妇女儿童医院进行超声检查并于海南现代妇女儿童医院终止妊娠者553例作为研究对象,分为PAS组(75例)和正常组(478例)。比较两组患者的临床资料,通过多因素Logistic回归分析孕产妇发生PAS的独立影响因素。构建反向传播(BP)神经网络模型,并进行模型评价。结果与正常组相比,PAS组年龄较大,孕次、产次、前置胎盘、既往剖宫产次数、清宫次数更多,早期子宫肌层厚度≤6 mm的患者比例更高(P<0.05)。孕次、产次、前置胎盘、既往剖宫产次数多、既往清宫次数多、宫腔手术史、早期子宫肌层厚度小是PAS发生的独立危险因素(P<0.05)。BP神经网络模型的隐含层节点数为3时,交叉验证的均方根误差最小。受试者操作特征(ROC)曲线、校准曲线和临床决策曲线显示该预测模型的区分度、准确性和有效性均较好。结论早期子宫肌层厚度与PAS发生率呈负相关,且经阴道超声测量瘢痕子宫再次妊娠早期子宫肌层厚度对PAS的预测价值较高。

Objective To analyze the predictive value of myometrium thickness of scar uterus measured by transvaginal ultrasound in the early stage of second pregnancy for placenta accreta spectrum(PAS).Methods From September 2020 to September 2021,553 cases who underwent ultrasound examination and terminated pregnancy with Hainan Modern Women and Children’s Hospital were selected as the study subjects.They were divided into PAS group(75 cases)and normal group(478 cases).Compared the data of groups,and the independent effect factors of PAS were analyzed by multivariate logistic regression.The back propagation(BP)neural network model is constructed and evaluated.Results Compared with the normal group,the PAS group was older,had more pregnancies,more deliveries,placenta previa,more previous cesarean sections,and more curettages,had myometrium thickness in the early stage less than 6 mm patients had a higher proportion(P<0.05).The independent risk factors of PAS were the number of pregnancies,parity,previous cesarean section,placenta previa,the number of previous curettages,uterine cavity surgery,the thickness of early uterine layer(P<0.05).When the number of hidden layer nodes of BP neural network model is 3,the validation have the smallest root mean square error.The receiver operating characteristic(ROC)curve,calibration curve and clinical decision curve show that it has great accuracy and effectiveness.Conclusion There is a negative correlation between the thickness of early uterine layer and the incidence of PAS,and the thickness of early uterine layer measured by transvaginal ultrasound has a high predictive value for PAS.