March 5, 2003 -- Childbearing increases a woman's risk of urinary incontinence later in life. If she has a cesarean section, she increases her risk some. If she has a vaginal birth, risk jumps even higher.
A large study of women in Norway sheds some light on the relation between childbirth and "urinary accidents," or urinary stress incontinence. Vaginal birth has often been cited as a main contributing factor, possibly because of damage to important muscle tissue or nerves, writes lead researcher Guri Rortveit, MD, with the University of Bergen.
However, only a few small studies have examined whether vaginal births caused more urinary problems than cesarean births, Rortveit writes. And these studies have been inconclusive.
His study appears in the March 6 issue of TheNew England Journal of Medicine.
Bergen and colleagues studied more than 15,000 women, all under age 65. Each was asked about incontinence and -- if they had ever given birth -- about method of delivery. The researchers also looked at other factors associated with an increased risk of urinary incontinence such as age, weight, and number of previous pregnancies.
Women who had delivered by cesarean section were at higher risk for incontinence than were women who had not given birth at all. But those who had had vaginal deliveries had even higher risk.
These results suggest that the mechanical strain during labor may add to the incontinence risk that comes with childbearing itself, Bergen writes. However, this evidence is not strong enough to increase the practice of cesarean delivery.
SOURCE: The New England Journal of Medicine, March 6, 2003.