Multiple vaginal deliveries increase the risk of permanent incontinence of flatus and urine in normal premenopausal women

This study was undertaken to evaluate the risk of permanent flatus or urinary incontinence after repeated vaginal deliveries. In 1989 a questionnaire on obstetric history and urinary and fecal incontinence was sent to a sample of 304 women selected from the birth records from 1976 to 1988; 242 responded (80 percent). Participants had one, two, or three vaginal deliveries, all without an obstetric tear of the anal sphincter. After the first, second, and third deliveries, 1.2, 1.5, and 8.3 percent developed permanent flatus incontinence. The risk was significantly increased after the third delivery compared with the first and second deliveries (odds ratio, 6.6; confidence interval, 2.4-18.3). Permanent urinary incontinence after the first, second, and third delivery developed in 3.3, 1.0, and 6.8 percent. The risk was significantly increased after the third delivery compared with the first and second (odds ratio, 3.2; confidence interval, 1.1-9.1). These results indicate that repeated vaginal deliveries increase the risk of minor anal and urinary incontinence, which were found to be a common problem in premenopausal women.