ObjectiveTo analyze the changes of pelvic floor structure in patients with stress urinary incontinence（SUI）in early stage of pregnancy

and to establish the ultrasound diagnosis model of SUI based on discriminant analysis.MethodsA total of 115 outpatients who had been given physical examination in early stage of postpartum in our hospital wereenrolled in and were randomly divided into the experimental group（98 training samples

including 52 SUI cases and 46 non-SUIcases）and the test group（17 validation samples

including 10 SUI cases and 7 non-SUI cases）. Pelvic floor ultrasound wasexamined in all subjects and the value of HBL

BND

URA

PVUA1

PVUA2 were recorded.Fisher’s stepwise discriminant analysiswas used to establish the diagnosis model and validate the according model

and the receiver operating characteristic（ROC）curve was drawn to evaluate its effectiveness in diagnosing SUI in early stage of pregnancy.ResultsIn training samples

the valueof HBL

BND

URA

PVUA1

PVUA2 in the SUI cases were significantly higher than those in the non-SUI cases

the differences werestatistically significant（all P<0.05）.Diagnostic model of SUI:Y0=-108.764+2.223 X2+1.187 X3+1.404 X5

Y1=-144.728+4.145 X2+1.879 X3+ 1.499 X5（Y0 represents the non-SUI cases

Y1 represents SUI cases

X2 represents BND

X3 represents URA and X5 represents PVUA2）.The results were obtained by self-test and cross-validation in the experimental group with an accuracy of94.9% and 93.9%.The results were checked in the test group with an accuracy of 82.3%.The area under the curve and 95%confidence interval of ROC curve in diagnosing early postpartum SUI were 0.939（0.895～0.983）.ConclusionThe multivariate combined diagnosis model established by Fisher discriminant analysis combined with pelvic floor ultrasound could objectivelyreflect the changes of pelvic floor function in patients with early postpartum SUI

providing a basis for early clinical diagnosis andintervention.