INTRODUCTION

Pelvic floor disorders (PFDs) include urinary and fecal incontinence, as well as pelvic organ prolapse. These disorders affect one-third of adult women in the United States, with substantial impact on their quality of life [1-4]. One study of 149,554 adult women reported an 11 percent risk of undergoing a single operation for pelvic floor disorders or incontinence by age 80 and found that 29 percent of these women required multiple surgeries [5]. Many other women have mild symptoms, which are managed conservatively with pessaries, pads, or no therapy. Thus, the burden of disease related to pelvic floor disorders is substantial.

An area of intense investigation is the effect of pregnancy and childbirth on a woman's risk of developing pelvic floor disorders and whether this risk can be modified by any interventions, such as planned cesarean delivery or avoidance of instrumental vaginal delivery. Some women have requested cesarean delivery for this reason. (See "Cesarean delivery on maternal request".)

The association of pelvic floor disorders (excluding fecal incontinence) with pregnancy and childbirth are reviewed here; information regarding fecal incontinence can be found separately. (See "Fecal incontinence related to pregnancy and vaginal delivery".)

ASSOCIATION OF PFD WITH PREGNANCY AND CHILDBIRTH

Numerous observational studies have reported that pelvic floor disorders are more prevalent among women who have delivered at least one child [6-17]. Examples from some representative studies are listed below:

• Among twins (mean age of 47 years, range 15 to 85 years), parous sisters with at least two births were three times more likely to report fecal incontinence [10], and four times more likely to report urinary incontinence than their nulliparous twin sisters [11].
• Among premenopausal women, parous women have a higher prevalence of stress urinary incontinence (SUI) and urinary urgency than nulliparous women [9].
• In contrast, among postmenopausal women, a history of pregnancy and childbirth appears to have little impact on the prevalence of urinary incontinence. Older nulliparous women are as likely to have urinary incontinence as older parous women [9,18]. It is assumed that the effects of other factors, such as comorbid medical conditions and age-related changes, outweigh the effect of previous pregnancies in these women [19].
• The Oxford Family Planning study, a prospective cohort study of more than 17,000 women followed for 17 years, found that, compared with nulliparity, the risk of hospital admission for pelvic organ prolapse increased markedly for the first (four-fold) and second birth (eight-fold), and then increased less rapidly for subsequent births (third: 9-fold; fourth: 10-fold) [20].
• Among postmenopausal women, the Women's Health Initiative observed that a history of at least one delivery was associated with twice the risk of pelvic organ prolapse (uterine prolapse, cystocele, rectocele) compared to nulliparous controls [7].
• In a survey of United States women, the proportion reporting at least one pelvic floor disorder increased with increasing parity [21].