WHAT DAMAGE DOES VAGINAL BIRTH CAUSE

描述(改编自申请人的摘要)：肌肉损伤， 出生时出现的盆底筋膜和括约肌 即使不是压力性尿失禁的最重要原因，也是其中之一 (隋)。大小便失禁女性患尿失禁的优势比为11.2 与可控性分娩相比，阴道分娩的比率是任何 其他因素。然而，阴道分娩导致SUI的机制， 是不被理解的。这项研究旨在阐明出生造成的损害是如何 导致SUI。这些见解将改进大小便失禁的治疗策略 治疗和预防。 SuI与a)尿路支持系统缺陷和b) 括约肌控制系统。然而，这两种损害都不是单独的， 充分解释了SUI的发生。这里提出的假设是 阴道分娩通过对这两者的联合损害而导致SUI 系统。为了验证这一假设，我们提出了病例对照设计。 初产妇压力性尿失禁(SI；n=80)， 产后坚持6个月。阴性对照将是无效的 可控性妇女(NC；n=80)和阳性对照；初产可控性 妇女(PC；n=80)经阴道分娩。他们将量化对尿路的支持 并使用超声、提肌和括约肌功能 强度测量和尿路压力研究。 为了分析基本假设，这些数据将被用来：1)展示 单独测量尿路支撑力或括约肌功能 将预测不到30%的SI病例。2)确定哪些组合 三个支持参数、三个括约肌参数及其 相互作用至少有80%的概率正确预测SI 用判别分析与PC或NC进行比较。3)构建一个 基于判别函数和分类的SUI预测模型 树表示支持参数的相对重要性，括约肌 参数及其相互作用。 二次假说涉及MRI上可见的解剖异常 对功能问题负责。该项目预计将显示： 1)失去支撑包括结缔组织断裂和/或提肌丧失 在MRI上可测量到的肛门内出血，表现为提肛肌大小的减小，以及2) 括约肌无力是由可量化的括约肌体积丢失引起的 平滑而有条纹的括约肌。解剖学上的相互关系 主要假设中列出的测量和功能参数将 确定功能异常的原因。 其他目标包括1)使用他们将构建的生物力学模型和 验证要测试的胎头和盆底的计算机模型 关于括约肌损伤机制的假说 支持损伤发生在阴道分娩过程中。2)这个项目应该 确定与SUI相关的产科参数的优先级。 这项研究的重要性在于它提供了关于 阴道分娩引起的特殊的功能和解剖缺陷。这 知识应该有助于设计未来出生时的伤害预防和帮助 为女性压力患者更合理的治疗选择奠定基础 大小便失禁。

DESCRIPTION (Adapted from the Applicant's Abstract): Damage to the muscles, fasciae, and sphincters of the pelvic floor that occurs at the time of birth is one of, if not the most important cause of stress urinary incontinence (SUI). Incontinent women have an odds ratio of 11.2 for having had a vaginal delivery compared with continent controls, twice the rate for any other factor. The mechanisms by which vaginal delivery causes SUI, however, are not understood. This study aims to clarify how damage caused by birth results in SUI. These insights will improve strategies for incontinence treatment and prevention. SUI is associated with defects in a) the urethral support systems and b) the sphincteric control system. Neither type of damage alone, however, adequately explains the occurrence of SUI. The hypothesis posed here is that vaginal birth causes SUI through a combination of damage to these two systems. To test this hypothesis, a case-control design is proposed enrolling as cases primiparous women with stress incontinence (SI; n=80), persisting 6 months postpartum. Negative controls will be nulliparous continent women (NC; n=80), and Positive controls; primiparous continent women (PC; n=80) delivered vaginally. They will quantify urethral support and sphincteric function in each of these groups using ultrasound, levator strength measurements and urethral pressure studies. For analysis of primary hypotheses, these data will be used to: 1) Show that measurements of either urethral support or sphincteric function alone will predict less than 30% of SI cases. 2) Identify which combinations of the three support parameters, three sphincter parameters, and their interactions have at least an 80% probability of correct prediction of SI compared with PC or NC by using discriminant analysis. 3) Construct a predictive model for SUI using discriminant functions and classification trees to indicate the relative importance of support parameters, sphincter parameters, and their interactions. Secondary hypotheses concern anatomical abnormalities visible on MRI responsible for functional problems. This project is expected to show that: 1) Loss of support involves connective tissue breaks and/or loss of levator ani bulk measurable on MRI as decrease in size of the levator ani, and 2) Sphincteric weakness results from quantifiable loss of sphincter bulk in the smooth and striated sphincter muscles. Correlation between anatomic measurements and functional parameters listed in the primary hypotheses will determine the cause of functional abnormalities. Other aims include 1) Using biomechanical models they will construct and validate a computer model of the fetal head and pelvic floor to test hypotheses concerning mechanisms of injury responsible for sphincter and support damage occurring during vaginal birth. 2) This project should establish the priority of obstetrical parameters associated with SUI. The importance of this research lies in its providing insights about the specific functional and anatomical defects caused by vaginal birth. This knowledge should help in devising future injury prevention at birth and help form the basis for more rational treatment selection in women with stress incontinence.