超声在剖宫产子宫再孕36～40周瘢痕厚度测量与破裂风险评估中的价值

Value of ultrasonography in the scar thickness measurement and rupture risk assessment for 36-40 weeks gravidas with the history of caesarean section

目的:探究超声在剖宫产子宫再孕36~40周瘢痕厚度的规范性测量方法及瘢痕破裂风险评估中的价值。方法:回顾性分析我院2016年12月-2017年12月间426例剖宫产子宫再孕36~40周孕妇,按再次生产时证实是否有子宫下段瘢痕肌层缺陷分为A、B和C组,其中A组(n=351)和B组(n=61)分别为剖宫产3年后和3年内的再孕孕妇,且再次术中或自然分娩未发现下段瘢痕肌层缺陷,C组(n=14)为再次剖宫产发现了下段瘢痕肌层缺陷,另设随机同期80例无剖宫产史孕36~40周孕妇为D组。产前超声对各组子宫前壁下段(剖宫产瘢痕处)肌层厚度进行观察、测量及风险评估,应用SPSS22.0统计软件对测量数据进行组间方差分析。结果:超声能清晰显示剖宫产再孕子宫瘢痕处肌层;产前超声测量A组前壁下段瘢痕肌层与B组间无显著差异(P=0.89),A、B两组与C组间均有显著性差异(P<0.05),A、B、C三组与D组间均有显著性差异(P<0.05)。结论:有无剖宫产史与子宫前壁下段肌层厚薄密切相关,瘢痕缺陷者产前超声肌层明显较无缺陷者薄;产前超声可以显示、测量并评价瘢痕缺陷风险,建议瘢痕肌层安全阈值为2.3mm。

Objective: To explore the value of ultrasonographic measurement of scar thickness in the risk assessment of scar rupture in 36-40 weeks’ pregnant women with caesarean section history. Methods:A retrospective analysis was made on 426 cases of 36-40 weeks’ pregnant women with prior cesarean section from December 2016 to December 2017 in our hospital. There were 14 cases(Group C)showed defects of lower scar myometrium confirmed before the second labour. The remain re-preg-nant women were diveded into Group A(n=351, >3 years after last cesarean section) and Group B(n=61, <3 years after last cesarean section) according to the interdelivery interval. And another 80 pregnant women without history of cesarean section were randomly assigned to group D as normal control group. The front wall of the uterus(cesarean section scar) muscle layer thickness in each subject was observed and measured by prenatal ultrasonographic and the risk was evaluated meanwhile.The interclass variance was analyzed by SPSS 22.0 with the measurement data. Results: The muscle layer of the re-pregnancy uterine in cesarean section was shown by ultrasonography clearly. There was little difference on the measurement results of anterior inferior segment of scar muscle layer with prenatal ultrasonographic between groups A and B(P=0.89), while the difference was significant between the re-pregnant women with and without defects of lower scar myometrium(P<0.05), and between pregnant women with and without cesarean section history(P<0.05). Conclusion: The thickness of the anterior inferior segment of the uterus is closely related to cesarean section history. The thickness of defective muscular layer shown by prenatal ultrasonographic is less than the normal one distinctly.Prenatal ultrasonography could display, measure, and evaluate the risk of scar defect, and the safety threshold of scar muscle layer is recommended to be 2.3 mm.