WHAT DAMAGE DOES VAGINAL BIRTH CAUSE

阴道分娩会造成什么伤害

• 批准号: 6086699
• 负责人: JOHN O.L. DELANCEY
• 金额: $ 6.7万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6086699
• 关键词: biomechanics; birth; clinical research; disease /disorder etiology; female; human pregnant subject; magnetic resonance imaging; mathematical model; model design /development; muscle function; muscle tone; obstetrics; parity; physical model; urinary bladder sphincter disorder; urinary incontinence

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.

描述（改编自申请人的摘要）：对肌肉的损伤， 筋膜和出生时发生的盆底括约肌 如果不是压力性尿失禁最重要的原因， （SUI）. 失禁妇女有一个11.2的优势比， 阴道分娩与大陆对照组相比，任何 其他因素。 然而，阴道分娩引起SUI的机制， 不被理解。 这项研究旨在阐明出生造成的损害是如何 结果是SUI。 这些见解将改善尿失禁的策略 治疗和预防。 SUI与a）尿道支持系统和B）尿道支持系统的缺陷有关 括约肌控制系统 然而，无论是哪种类型的损害， 充分解释了SUI的发生。 这里提出的假设是 阴道分娩是通过对这两个器官的损伤 系统. 为了验证这一假设，提出了病例对照设计 入选压力性尿失禁的经产妇（SI; n=80）， 产后持续6个月。 阴性对照为未经产 大陆女性（NC; n=80）和阳性对照;经产大陆 经阴道分娩的妇女（PC; n=80）。 他们会量化尿道支持 和括约肌功能在这些组中的每一个使用超声，提肌 力量测量和尿道压力研究。 对于主要假设的分析，这些数据将用于：1）显示 尿道支持或括约肌功能的测量 将预测不到30%的SI病例。 2)确定哪些组合 三个支撑参数，三个括约肌参数，以及它们的 相互作用至少有80%的概率正确预测SI 用判别分析法对PC和NC进行比较。 3)构建 使用判别函数和分类的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。 次要假设涉及MRI上可见的解剖结构异常 负责功能问题。 预计该项目将表明： 1)支撑丧失涉及结缔组织断裂和/或提肌丧失 在MRI上可测量的肛体积为肛提肌尺寸减小，以及2） 括约肌无力是由于括约肌体积的可量化损失， 平滑和横纹括约肌。 解剖学之间的相关性 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， 验证胎儿头部和骨盆底的计算机模型， 关于括约肌损伤机制的假说， 支持阴道分娩时发生的损伤。 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功能和解剖缺陷。 这 知识应该有助于设计未来的出生时伤害预防， 为有压力的女性更合理的治疗选择奠定基础 失禁