Review on March 30, 2009
Doctors tested approx 18,500 of women from the same Norwegian county (Nord-Trondelag) to determine whether a genetic predisposition may play a part in the development of urinary incontinence among women, a common result of menopause. The familial risk of urinary incontinence was investigated in daughters, granddaughters and sisters of incontinent women. The study was divided into two parts; mother to daughter and older sisters to younger sisters. It compared the risk of urinary incontinence in the daughters of incontinent women versus the daughters of continent women as well as between sisters of incontinent older sisters versus sisters of continent older sisters. Proper adjustments were made for age, body mass index, and number of children of the women at risk.
Sixty-five percent of the mothers and sixty-four percent of the older sisters first surveyed in 1995 participated in the 2004 follow up survey. The results revealed that daughters of mothers with any type of urinary incontinence had a 1.3 fold risk of incontinence themselves. The risk of daughters to suffer the same type of incontinence as their mother was the higher than suffering different types. (Urinary incontinence develops into three stages: stress incontinence when pressure on the bladder causes leakage, urge incontinence when leakage is caused by an oversensitive bladder and mixed incontinence when the bladder doesn't empty completely, leading to frequent urination or dribbling.)
In the few cases where urinary incontinence could be investigated in the grandmothers, mothers and daughters, no increased risk was found in granddaughters if only the grandmothers were incontinent. When both grandmothers and mothers had urinary incontinence however, the risk for incontinence in granddaughters was 2.4 fold. Type of incontinence could not be tested due to too few families to study. Younger sisters had a 1.6-fold increase risk of urinary incontinence if their older sisters were incontinent.
The conclusion of the study reveals an increased chance for incontinence among menopausal women if their mothers and older sisters suffer(ed) from incontinence. Specifically, daughters were more likely to develop stress or mixed incontinence if their mother had these conditions as were the sisters of older siblings with these types of urinary incontinence. Severe urge incontinence is the least common among young women.