Effects of conservative management following obstetric anal sphincter injury – a systematic review

Background Obstetric anal sphincter injury (OASI) is associated with an increased risk of anal incontinence (AI), which can have a substantial impact on quality of life. Conservative management strategies are commonly used in clinical practice, including physical therapy, both in the immediate postpartum period and longer term, but evidence of their effectiveness remains limited. Therefore, this systematic review aimed to evaluate the effects of conservative management strategies on AI and related outcomes following OASI.Methods MEDLINE, CINAHL and PEDro were searched from inception until January 2025. Findings were synthesised narratively and complemented with albatross plots.Results Thirteen randomised controlled studies (n = 1082 participants) were identified, evaluating biofeedback, electrical stimulation, pelvic floor muscle exercise, and bowel regulating treatment. Across the studies, treatment protocols, intervention durations, and outcome measures varied, for the interventions studied. Although within-group effects were observed, no consistent between-group differences were found between the interventions and their comparators for AI. The certainty of evidence was deemed low.Conclusion The certainty of evidence was low for all three outcomes, with no clear superiority between interventions despite within-group improvements. Heterogeneity in populations, intervention timing, and content limits firm conclusions, highlighting the need for well-designed trials.