Familial predisposition to pelvic floor dysfunction: prolapse and incontinence surgery among family members and its relationship with age or parity in a Swedish population

ObjectiveTo estimate the relationship between heredity and proband's age/parity on the risk of undergoing surgery for pelvic organ prolapse and stress incontinence.Study design: Swedish population based study. Data from two national Swedish registers were used: the Hospital Discharge Register, National Board of Health and Welfare, containing information on all in-patient surgical procedures on Swedish hospitals, and the Multi-Generation Register, Statistics Sweden, containing information on individuals belonging to the same family. Women who had a surgical procedure for urinary incontinence or genital organ prolapse between the years 1987 and 2002 were identified (probands). Mothers and sisters of the probands were identified and information on incontinence or prolapse operations was linked to those relatives from the Hospital Discharge file, after which adjusted analyses were performed.ResultsSisters to probands had a relative risk (RR) of 4.69 (95% confidence intervals (CI) 4.49-48.9) and mothers a RR of 2.17 (95% CI 2.07-2.27) for pelvic floor surgery. For sisters the risk decreased with increasing age and parity of the proband.ConclusionSisters and mothers of women operated for urinary incontinence/urogenital prolapse had a higher risk of surgery for pelvic floor conditions, in particular sisters of women operated at a young age (<50) and with a low parity. This suggests that heredity plays a lesser role for the development of pelvic floor dysfunction at older age and with increasing parity.