The effects of labour and delivery on the pelvic floor.

Increasing public and professional attention has recently been focused on the issue of both faecal and urinary incontinence following childbirth and these symptoms are sometimes being cited as indications for elective caesarean section. Faecal incontinence has a female-to-male preponderance of 8:1, consistent with childbirth as the principal causative factor, although most symptomatic women do not seek medical advice until after the menopause. Similarly, urinary stress incontinence is almost an exclusively female phenomenon. Obstetric injury may take the form of direct muscular damage to the anal sphincter, as occurs during a third-degree tear, and/or may be the result of cumulative damage to the pudendal nerves. Mechanical, neural and endocrine factors may all play a causative role in faecal incontinence. Symptoms are rarely volunteered by the patient, and may be present for many years after the index pregnancy, and clinical examination alone may fail to detect specific abnormalities. The performance of anal manometry, endoanal ultrasound, urodynamics and neurophysiology studies of the pelvic floor may help to increase the diagnostic yield. Treatment for both urinary and faecal incontinence is available in the form of physiotherapy, fluid and dietary manipulation and in more severe cases, surgery. Adequate primary management of third-degree tears requires careful appraisal as this injury, in particular, is the most important risk factor for subsequent faecal incontinence symptoms. In this chapter we aim to outline the mechanism of damage to the pelvic floor during childbirth, concentrating primarily on anal sphincter damage. We describe the necessary investigations, follow-up and treatment which women with significant pelvic floor damage should receive following delivery, and we finally discuss the issue of further deliveries and, specifically, the current place of caesarean section. Copyright 2001 Harcourt Publishers Ltd.