Vaginal delivery parameters and urinary incontinence: The Norwegian EPINCONT study

Objective The study was undertaken to investigate the effect of nine delivery parameters on urinary incontinence in later life. Study design Incontinence data from the EPINCONT study were linked to the Medical Birth Registry of Norway. Effects of birth weight, gestational age, head circumference, breech delivery, injuries in the delivery channel, functional delivery disorders, forceps delivery, vacuum delivery, and epidural anesthesia were investigated. The study covered women younger than 65 years, who had had vaginal deliveries only (n = 11,397). Results Statistically significant associations were observed between any incontinence and birth weight 4000 g or greater (odds ratio [OR] 1.1, 95% CI 1.0-1.2); moderate or severe incontinence and functional delivery disorders (OR 1.3, 95% CI 1.1-1.6); stress incontinence and high birth weight (OR 1.2, 95% CI 1.1-1.3) and epidural anesthesia (OR 1.2, 95% CI 1.0-1.5); and urge incontinence and head circumference 38 cm or larger (OR 1.8, 95% CI 1.0-3.3). Conclusion The effects were too weak to explain a substantial part of the association between vaginal delivery and urinary incontinence, and statistically significant results may have incurred by chance.