These findings add weight to the theory that a genetic predisposition may play a part in the development of this common and burdensome condition among women.
The research team investigated the risk of urinary incontinence in the daughters, granddaughters, and sisters of over 2,000 incontinent women compared to the risk for almost 6,000 women with continent relatives.
Daughters of mothers with urinary incontinence had a 1.3-fold risk of being incontinent. If mothers had severe symptoms then their daughters had a close to 2-fold risk of such symptoms.
Female siblings had a 1.6-fold increased risk of urinary incontinence if their older sisters were incontinent. The familial risk found in the study was present for both symptoms of stress and urge incontinence.
"The symptoms of urinary incontinence are likely to have a complex cause, and known risk factors such as increasing age, pregnancy and childbirth, and high body mass index may further increase the risk among women with a genetic predisposition," conclude the authors.