Inflammatory bowel disease and risk of perineal injury in primiparous vaginal births: a retrospective cohort study

BACKGROUND: The association between inflammatory bowel disease (IBD) without active perineal disease and the risk of perineal trauma during vaginal birth remains unclear. Thus, we aimed to determine whether IBD without active perianal disease is independently associated with perineal trauma. METHODS: A retrospective cohort study including all primiparous women with singleton, cephalic, term pregnancies who delivered vaginally at a tertiary medical center between 2012 and 2023. Women with IBD without active perianal disease were compared with women without IBD. Women with active perianal disease were excluded according to institutional guidelines. The primary outcomes included overall perineal injury, defined as any spontaneous perineal tear, labial laceration, obstetric anal sphincter injury (OASI), and episiotomy. Multivariable logistic regression was performed to assess the association between inflammatory bowel disease and perineal trauma, adjusting for potential confounders. RESULTS: Among 45,250 primiparous women, 244 women (0.5%) had IBD. Overall perineal injury rates were similar between the IBD and control groups (84.0% vs. 85.4%; P = .553). OASI was comparable (0.4% vs. 0.9%; P = .728), and episiotomy rates did not differ significantly. In multivariable analysis, IBD was not associated with perineal trauma (aOR 0.82; 95% CI 0.56-1.19, P = .288). Independent predictors included vacuum-assisted delivery, higher birthweight, occiput posterior presentation, prolonged second stage, and epidural analgesia. Subgroup analysis showed no differences between ulcerative colitis and Crohn's disease. CONCLUSION: IBD without active perianal disease does not increase the risk of perineal injury in primiparous women undergoing term vaginal delivery. Vaginal birth is an appropriate mode of delivery in this population.