| Objective : To estimate the value of myometrial lower uterine segment thickness measurement by high frequency ultrasound to predict cesarean scar defect,and to analyze risk factors of cesarean scar defect.Methods:A prospective study was conducted on 323 cases of ERCS pregnant women in the first half of 2019 in General Hospital of Northern Theatre Command.The myometrial lower uterine segment thickness was measured by transabdominal high-frequency ultrasound for 1-3 days before cesarean section,graded and compared with the uterine scar seen by the surgeon during cesarean section.ROC curve was assessed for the myometrial thickness of lower uterine segment in women in group cesarean scar defect,and screened the risk factors of cesarean scar defect by single factor and multiple logistic regression analysis.Results:(1)The myometrial lower uterine segment thickness measured by ultrasound was the thickest in Grade I(LUS was continuous and well developed)and the thinnest in Grade III(LUS was either translucent with visible content or well-circumscribed defects)(p < 0.01).The thickness of myometrial lower uterine segment was negatively correlated with the grade of the uterine scar evaluated by the surgeon during cesarean section(r-0.468,p < 0.01).(2)The ROC curve shows that measurement of the myometrial lower uterine segment thickness can better predict cesarean scar defect,and the cutoff is 1.2 mm.Therefore,when the myometrial lower uterine segment thickness≤1.2 mm,the possibility of cesarean scar defect is high.(3)The myometrial lower uterine segment thickness measurement by high frequency ultrasound≤1.2 mm,the high weight of the infant in this pregnancy,and the previous cesarean done in preterm are the risk factors for cesarean scar defect(P < 0.05).Conclusion : Myometrial lower uterine segment thickness measurement by high frequency ultrasound in late third trimester in pregnant patients with previous cesarean section can help to diagnose the cesarean scar defect,to guide the patients with previous cesarean section when deciding the approach to delivery,and expected to improve the safety of TOLAC. |