Obstetric Factors

Obstetric injury is thought to be a principal factor contributing to the development of pelvic floor dysfunction (prolapse, urinary and fecal incontinence). This is attributed to direct muscular and connective tissue injury or to denervation injury to the pudendal nerve. There is question as to whether the mode of obstetric delivery, or just the event of being pregnant, has a role in developing prolapse. In a case-control study, patients who delivered their first child before the age of 25 years had an almost fourfold increase of developing prolapse.7 Up to 50% of all parous women have some degree of prolapse, with 10% to 20% being symptomatic.13 Elective cesarean delivery in a non-labored patient has been speculated to protect the pelvic floor from damage leading to prolapse; however, to date there are no prospective randomized studies to support this theory. It has been well established that vaginal parity, notably the first, is an independent risk factor for the future development of genital prolapse. It was demonstrated that the odds ratio was 3.0 for women who had one vaginal delivery and 4.5 for women with a history of two or more vaginal deliveries.14 Mant et al.2 analyzed risk factors for genital prolapse in 17032 women in family planning clinics across England and Scotland. In those patients who were diagnosed with prolapse, parity was shown to have the strongest relationship to the development of prolapse. The risk of prolapse increased with each child, up to two children; that is, a woman with two children was eight times more likely to develop prolapse compared with a nulli-parous patient.

The event of a vaginal delivery results in dilation and stretching of the pelvic floor - nerves, connective tissue supports including the uterosacral and cardinal ligaments, endopelvic fascia, and the perineal body. Stretching of the pudendal nerve during vaginal delivery is thought to be a major cause of nerve damage leading to pelvic floor dysfunction including prolapse as well as incontinence. The type of obstetric event, which results in a neuropathy, has been evaluated in studies assessing pudendal nerve function. Tetzschner and colleagues15 demonstrated an increase in terminal motor latency of the pudendal nerve (PTML) in women who underwent a vaginal delivery. In a study by

Sultan et al.,16 PTML was compared in women beyond 34 weeks gestation who either delivered vaginally or by elective cesarean delivery. Terminal motor latency of the pudendal nerve was significantly more prolonged in those women who had a vaginal delivery compared with women who had an elective cesarean delivery either primiparous or multiparous. Women who had a cesarean delivery after the onset of labor also had prolongation of PTML.16 Instrumental vaginal delivery with forceps has been shown to be responsible for a greater incidence (fourfold increase) of pelvic floor dysfunction compared with vaginal deliveries without forceps. This determination is based on objective data including physical examination.17

Pregnancy Guide

Pregnancy Guide

A Beginner's Guide to Healthy Pregnancy. If you suspect, or know, that you are pregnant, we ho pe you have already visited your doctor. Presuming that you have confirmed your suspicions and that this is your first child, or that you wish to take better care of yourself d uring pregnancy than you did during your other pregnancies; you have come to the right place.

Get My Free Ebook

Post a comment