Reproductive history of parous women and urinary incontinence in midlife: A National Birth Cohort follow-up study

Objective

To investigate how reproductive history was associated with urinary incontinence in midlife.

Design

A follow-up study.

Setting

Denmark.

Population

A total of 39 977 mothers who participated in the Maternal Follow up (2013–2014) in the Danish National Birth Cohort. National registries provided their reproductive history.

Methods

How parity, mode of birth and obstetric tears associated with urinary incontinence were estimated with adjusted odds ratios (OR) and 95% CI using logistic regression.

Main outcome measures

Self-reported urinary incontinence including subtypes stress, urge and mixed urinary incontinence.

Results

At an average age of 44 years, the prevalence of any urinary incontinence was 32% (21% stress, 2% urge, and 8% mixed urinary incontinence). Women with two births more often had urinary incontinence than women with one birth (OR 1.20, 95% CI 1.10–1.31). Compared with women with only spontaneous births, a history of only caesarean sections was associated with much lower odds of urinary incontinence (OR 0.39, 95% CI 0.35–0.42) and a history of instrumental births with slightly lower odds (OR 0.92, 95% CI 0.86–0.98). Compared with no tear/first-degree tear as the largest tear, episiotomy was associated with less urinary incontinence (OR 0.91, 95% CI 0.86–0.97) whereas third/fourth-degree tears were associated with more (OR 1.14, 95% CI 1.04–1.25). Findings were mainly explained by similar associations with stress and mixed urinary incontinence.

Conclusions

Vaginal birth was associated with a higher risk of long-term urinary incontinence, but our results indicate that this risk may be reduced by shortening the second stage of birth.