# Urinary incontinence 12 years after obstetric anal sphincter injury in a longitudinal case control study

## TL;DR

This study found that 12 years after childbirth, women with and without anal sphincter injuries had similar urinary incontinence symptoms and quality of life impacts.

## Contribution

The study provides long-term evidence on urinary incontinence following obstetric anal sphincter injury, showing no significant difference in symptoms 12 years postpartum.

## Key findings

- At 12 years postpartum, mean IIQ-7 scores were similar between OASIS and control groups.
- UDI-6 scores increased significantly over time in the entire cohort, with a more pronounced rise in the control group.
- The severity of UI symptoms progressed significantly over time within the entire cohort.

## Abstract

Evidence on long-term urinary incontinence (UI) after obstetric anal sphincter injury (OASIS) is scarce. This longitudinal case-control follow-up study assessed the evolution of urinary symptoms and their impact on quality of life 12 years after vaginal delivery in women with and without OASIS, comparing the findings with previous data from the same study population. A questionnaire, including the Urogenital Distress Inventory (UDI-6; evaluating the degree of bother caused by UI) and the Incontinence Impact Questionnaire (IIQ-7; evaluating the impact of UI on quality of life), was mailed to 242 previous participants (63 women with OASIS and 179 matched controls). The participation rate reached 76%. At 12 years postpartum, mean IIQ-7 scores were similar between groups (1.1 ± 2.6 for OASIS vs. 0.8 ± 1.7 for controls, p = 0.300). The UDI-6 scores increased significantly across the entire cohort (2.5 at 6 years vs. 3.3 at 12 years, p < 0.001), with a more pronounced rise in the control group (2.3 at 6 years vs. 3.2 at 12 years, p < 0.001) compared to the OASIS group, where the difference was not statistically significant (3.0 at 6 years vs. 3.5 at 12 years, p = 0.379). At 12 years, the severity of urinary symptoms and their impact on quality of life were comparable between women with OASIS and those without, contrasting with findings at 6 years. Within the entire cohort, the severity of UI symptoms progressed significantly over time.

The online version contains supplementary material available at 10.1038/s41598-026-36123-y.