Obstetric Factors Associated With Postpartum SUI And Pelvic Floor Collagen Changes In Third Trimester Pregnancy

Objectives:1.Investigate the histological characteristics and collagen status in vaginal wall of thewomen at third trimester pregnancy by using immunohistochemistry and imageanalysis technique,preliminary discuss the relation between the change of pelvicsupporting structures and higher incidence of third trimester pregnancy SUI.2. Explore the different obstetric factors and postpartum SUI relationship.Materials and Methods:1.All subject were divided into two groups A full-term pregnancy group (n=20), thepreterm group (n=13).The vaginal wall were obtained from vagina side incision orthe laceration of vagina from the subjects. Tissue after fixation, embedding, sectioning,stained with Masson, observe the histological features, and immunohistochemicalmethod to detect the content of type Ⅰ and type Ⅲ collagen.2. Selected those women with routine antenatal examination and delivery in ourhospital Obstetrical Dept. We used questionnaire or telephone follow-up to get theinformation of the subjects in third trimester pregnancy,6weeks and6monthspostpartum.Results:1. Masson staining and morphological comparison: We can see the collagen fiberswere blue. Compared to the preterm group, the collagen fibers were stained withshallow, arrange relatively sparse, fibroblast density decreased, arranged in loose infull-term pregnancy group.2. Immunohistochemistry and image analysis: Collagen positive area in the slice islight brown to dark brown. The full-term pregnancy group collagen positive area,positive unit were less than the preterm group (P <0.05), difference has significance. Full-term group into two groups, One group is SUI and another group of non-SUI,collagen positive area and positive unit in the two groups have significant differences.3. Sort of follow-up data: in the full-term pregnancy group, the incidence of SUI inlate pregnancy is44.8%. Full-term birth, elective caesarean section, premature birthby6weeks postpartum, SUI incidence was31.3%,10.8%,9.1%. Chi-square test,x~2=16.98, P=0.001, that the incidence of SUI between the three groups there was asignificant difference. The incidence of SUI in which the full-term group withcesarean section group (x~2=8.36, P=0.004) and preterm group (x~2=5.92, P=0.025)have significant differences, still can not believe that the preterm group and caesareansection group differ (P=0.787). SUI incidence was further decline in six monthspostpartum.4.Risk factors of postpartum urinary incontinence pregnancy SUI (P=0.016, OR=15.032), the body mass index before delivery (P=0.001, OR=2.432), birth weight (P=0.012, OR=1.008) and vaginal delivery (P=0.002, OR,=1.451), second stage oflabor(P=0.012, OR=1.014).Conclusion:1. In late pregnancy, the type Ⅰ and type Ⅲ collagen content in female pelvic floorreduced, suggesting that pelvic floor connective tissue changes during pregnancy is animportant factor for pregnancy SUI.2. Vaginal delivery, body mass index before delivery, birth weight, second stage oflabor and gestational SUI are the risk factors of postpartum SUI. Elective cesareansection is protective factors of postpartum SUI.3. The incidence of SUI in third trimester of pregnancy is higher than postpartum SUI.The incidence of postpartum SUI reduced with time. Prompted that the pelvic floorstructure and function damage caused by pregnancy and delivery maybe graduallyrepair with the end of pregnancy.