Vaginal birth is believed to be a major etiologic factor in urinary incontinence in women. Pelvic muscle exercises have been shown to decrease urine loss in nonpregnant women with incontinence, but data on pregnant women have not been adequately addressed. Sampselle and colleagues studied the effect of a program of pelvic muscle exercises on incontinence symptoms and pelvic muscle strength up to one year post delivery.

The authors studied primiparous patients with no history of incontinence. At 20 weeks of gestation, 34 expectant mothers were randomly assigned to a treatment group that received standardized instruction in pelvic muscle exercises; 38 women were assigned to the control group. Data on urinary incontinence and pelvic muscle strength were collected at 20 and 35 weeks of gestation and at six weeks, six months and 12 months post-partum in both groups.

The two groups were comparable at baseline in terms of age, level of education, symptoms of urinary incontinence and maximum voluntary contraction force. By 35 weeks of gestation, the treatment group demonstrated significantly less urinary incontinence. These differences were also measured in late pregnancy and at six months postpartum. At one year following birth, the differences between the groups had disappeared. Adherence to the exercise program at least 75 percent of the time was reported by 85 percent of the treatment group at 35 weeks of gestation. Adherence ranged from 62 to 90 percent during the post-partum year.

The authors conclude that pelvic muscle exercises reduce symptoms of urinary incontinence in late pregnancy and up to six months postpartum. They speculate that the exercise group experienced more rapid rehabilitation because of improved muscle tone and functional reserve. The authors recommend that women who are pregnant or who are planning an eventual pregnancy be offered instruction in pelvic muscle exercises, particularly those in whom pelvic muscle weakness is detected.