The prospective study was based on 21,864 premenopausal women, aged 37 to 54, asked to report their use of contraceptives over a three-year period.

Women who used oral contraceptives were found to be 27 per cent more likely to experience leakage at least weekly compared with women who had never taken them.

The risk was found to increase significantly with increasing duration of contraception use.

The researchers, from the Brigham and Women's Hospital and Harvard Medical School, said: 'Our study findings suggest that oral contraceptive pill use may be associated with a modestly increased risk of urinary incontinence among premenopausal women.

'However, this is one of the first reports of such an association and, thus, further research is needed to confirm our findings and investigate possible mechanisms.'

No biological link between oral contraceptive use and incontinence has yet been established, but changes in collagen composition and increased bladder contractility have been proposed, said the researchers.

GPletters@haymarket.com

• Journal of Urology Online 2009

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