RESUMO
BACKGROUND: Anal incontinence is a major concern following delivery with obstetric anal sphincter injury (OASIS), and has been related to the degree of sphincter tear. OBJECTIVE: The aims of this study were (1) to evaluate whether women with a fourth-degree OASIS in the first delivery have an increased risk of long-term anal and fecal incontinence after a second delivery, and (2) to assess the impact of mode of second delivery on anal incontinence and related symptoms in these patients. MATERIALS AND METHODS: We performed secondary analyses of a national questionnaire study in all Danish women with an OASIS in their first delivery and 1 subsequent delivery, both deliveries in 1997 to 2005. The questionnaires were sent a minimum of 5 years since the second delivery. In Denmark, women with anal incontinence after a delivery with OASIS are recommended elective cesarean deliveries in subsequent pregnancies. We performed uni- and multivariable logistic regression analyses to evaluate the outcomes. RESULTS: In total, 2008 patients had an OASIS, of whom 12.2% (n = 245) had a fourth-degree tear in the first delivery. The median follow-up time since the first delivery with OASIS was 11.6 years (IQR, 10.2-13.2 years) and since the second delivery 8.5 years (IQR, 7.1-10.1 years). Women with a fourth-degree sphincter injury in the first delivery were at higher risk for anal incontinence (58.8%, n = 144) as well as fecal incontinence (30.6%, n = 75) than patients with a third-degree injury in the first delivery (41.0%, n = 723, and 14.6%, n = 258, respectively). The differences between groups persisted after adjustment for important maternal, fetal, and obstetric characteristics (adjusted odds ratio [aOR], 2.14; 95% confidence interval [CI], 1.52-3.02; P < 0.001 for anal incontinence; and aOR, 2.49; 95% CI, 1.73-3.56; P < 0.001 for fecal incontinence). In subgroup analyses of patients with fourth-degree anal sphincter injury in the first delivery, the mode of second delivery was not associated with the risk of anal incontinence (aOR, 0.97; 95% CI, 0.41-1.84; P = 0.71) or fecal incontinence (aOR, 1.28; 95% CI, 0.65-2.52; P = 0.48). The effect of the mode of the second delivery did not differ between women with a fourth-degree OASIS and those with a third-degree injury with regard to both anal (P = 0.09) and fecal (P = 0.96) incontinence. CONCLUSION: After a second delivery, women with a fourth-degree OASIS in the first delivery have a higher risk of long-term anal and fecal incontinence than women with a third-degree sphincter injury. Adjusted odds of long-term anal and fecal incontinence did not differ significantly by mode of second delivery. Women with a fourth-degree OASIS should be informed about the increased risk of long-term anal incontinence and advised that subsequent elective cesarean delivery is not protective.