Study On Function Of Levator Ani Muscle In Women At Different Stages Of Pregnancy By Transperineal Pelvic Floor Ultrasound

Objective:Transperineal pelvic floor ultrasound was used to observe the pelvic floor of pregnant women dynamically and continuously,the position and mobility of pelvic floor organs,the parameters and its changes of levator ani muscle hiatus were measured and calculated at different stages of pregnancy,and the effects of pregnancy on female pelvic floor structure were analyzed statistically,to evaluate the changes of pelvic floor function during pregnancy in order to provide imaging evidence for clinical prevention and early diagnosis of female Pelvic floor dysfunction disease.Methods:67 cases of first pregnancy women were selected from the archives of the Department of Obstetrics and gynecology of the first affiliated hospital of Gannan Medical College from October 2020 to October 2022,according to the course of pregnancy,the patients were followed up in three stages:early pregnancy(11-14weeks),middle pregnancy(22-24 weeks)and late pregnancy(34-37 weeks).Finally,58 cases were followed up completely,and 9 cases were lost in midway.Before the examination,investigated and recorded carefully whether the subject currently had symptoms of stress urinary incontinence,and counted separately the detection rate of SUI in early,middle and late pregnancy.We used transperineal pelvic floor ultrasound for examination.Firstly,measured the area(S),perimeter(C),bilateral levator urethra gap(R-LUG,L-LUG)of levator ani muscle hiatus in resting and anal contraction state,and calculated the area change(△S),perimeter change(△C),bilateral levator urethra gap change(R-△LUG,L-△LUG)and levator ani muscle contraction strain rate(ε)(from resting state to anal contraction state)in systolic period.Secondly,in resting and anal contraction state,measured respectively the distance between bladder neck(BLN),cervix external(CXE),rectum ampulla(RA)and the horizontal reference line and the vertical reference line at the posterior inferior border of the pubic symphysis,then calculated the vertical movement and horizontal movement of BLN,CXE,RA in the systolic period.All data were analyzed and processed with SPSS26.0 statistical software.The measurement data were expressed with mean±standard deviation(±s),the counting data is expressed in rate(%).Single factor repeated measurement analysis of variance was used to compare the data of normal distribution,Kruskal-Wallis H rank test was used to compare the data of non-normal distribution,and trend x~2test was used to compare the data of count data.There was significant difference in P<0.05.Results:1.The S,C,R-LUG,L-LUG of levator ani muscle hiatus in resting state and anal constriction stateincreased gradually with the increase of gestational age,the difference was statistically significant(P<0.05).In resting and anal constriction state of pregnancy,the distance between BLN,CXE,RA and the horizontal reference line at the posterior lower edge of pubic symphysis decreased with the increase of gestational age,the difference was statistically significant(P<0.05).In resting and anal constriction state of pregnancy,the distance between BLN,CXE,RA and the vertical reference line at the posterior inferior border of pubic symphysis increased with the increase of gestational age,the difference was statistically significant(P<0.05).2.The△S,△C of levator ani muscle hiatusin systolic period decreased gradually with increasing of gestational age(P<0.05),the difference was statistically significant(P<0.05);while the R-△LUG,L-△LUG did not change with the increase of gestational age,there was no significant difference(P>0.05).The strain rate of levator ani muscle decreased with the increase of gestational age,the difference was statistically significant(P<0.05).The vertical mobility and the horizontal mobility of BLN,CXE and RA in systolic period decreased with the increase of gestational age,the difference was statistically significant(P<0.05).3.The detection rate of SUI was 15.52%in the first trimester,25.86%in the second trimester and 43.10%in the third trimester.There was no significant difference in the detection rate of SUI between the second trimester and the first trimester,the third trimester and the second trimester(P>0.05);the detection rate of SUI in the third trimester was higher than that in the first trimester,the difference was statistically significant(P<0.05).Conclusion:1.The longer the pregnancy,the more obvious the relaxation of pelvic floor supporting structure,the weaker the supporting effect of pelvic floor structure,the worse the contraction function of levator ani muscle,and the higher the detection rate of SUI in late pregnancy than in early pregnancy.2.The change of the distance between the pelvic floor organs and the posterior inferior border of pubic symphysis during pregnancy and the change of the horizontal movement in systolic period can be used as new indexes to evaluate the pelvic floor function.3.TPUS can accurately observe the pelvic floor structure at different stages of pregnancy and effectively evaluate the changes of pelvic floor function during pregnancy,which can provide imaging reference for clinical prevention and early diagnosis of PFD.