Familial risk of urinary incontinence in women: population based cross sectional study.

Objective: To determine whether there is an increased risk of urinary incontinence in daughters and sisters of incontinent women.
Design: Population based cross sectional study.
Setting: EPINCONT (the epidemiology of incontinence in the county of Nord-Trøndelag study), a substudy of HUNT 2 (the Norwegian Nord-Trøndelag health survey 2), 1995-7.
Participants: 6021 mothers, 7629 daughters, 332 granddaughters, and 2104 older sisters of 2426 sisters.
Main Outcome Measures: Adjusted relative risks for urinary incontinence.
Results: The daughters of mothers with urinary incontinence had an increased risk for urinary incontinence (1.3, 95% confidence interval 1.2 to 1.4; absolute risk 23.3%), stress incontinence (1.5, 1.3 to 1.8; 14.6%), mixed incontinence (1.6, 1.2 to 2.0; 8.3%), and urge incontinence (1.8, 0.8 to 3.9; 2.6%). If mothers had severe symptoms then their daughters were likely to have such symptoms (1.9, 1.3 to 3.0; 4.0%). The younger sisters of female siblings with urinary incontinence, stress incontinence, or mixed incontinence had increased relative risks of, respectively, 1.6 (1.3 to 1.9; absolute risk 29.6%), 1.8 (1.3 to 2.3; 18.3%), and 1.7 (1.1 to 2.8; 10.8%).
Conclusion: Women are more likely to develop urinary incontinence if their mother or older sisters are incontinent.