Systematic Review and Meta-analysis of the Prevalence of Levator Ani Avulsion with Obstetric Anal Sphincter Injury and its Effects on Pelvic Floor Dysfunction

Zohra Amin; Ahmed Khairy El-Naggar; Ifeoma Offiah; Anupreet Dua; Robert Freeman

doi:10.1007/s00192-024-05756-w

Systematic Review and Meta-analysis of the Prevalence of Levator Ani Avulsion with Obstetric Anal Sphincter Injury and its Effects on Pelvic Floor Dysfunction

Int Urogynecol J. 2024 Mar 25. doi: 10.1007/s00192-024-05756-w. Online ahead of print.

Authors

Zohra Amin¹, Ahmed Khairy El-Naggar², Ifeoma Offiah³, Anupreet Dua⁴, Robert Freeman⁴

Affiliations

¹ The Royal Oldham Hospital NHS Trust, Oldham, UK. Zohra.amin1@nhs.net.
² University Hospitals of Derby & Burton NHS Trust, Derby, UK.
³ North Bristol NHS Trust, Bristol, UK.
⁴ University Hospitals Plymouth NHS Trust, Plymouth, UK.

PMID: 38523161
DOI: 10.1007/s00192-024-05756-w

Abstract

Introduction and hypothesis: The objective was to evaluate the prevalence of levator ani avulsion (LAA) among primiparous women with obstetric anal sphincter injury (OASI) and how this association could affect future pelvic floor dysfunction.

Methods: Three electronic databases (MEDLINE/PubMed/EMBASE) were searched in December 2018 and again in October 2022. Nine full-text articles were included in the analysis. The exclusion criteria were language other than English, studies not based on primiparous women only, conference abstracts, and evaluation without ultrasound or MRI.

Results: The overall prevalence of LAA was 24% (95% CI: 18-30%). Those with OASI, were at a higher risk of LAA, OR 3.49 (95% CI: 1.46 to 8.35). In women with LAA + OASI versus OASI alone, Three of Five studies showed worsened AI symptoms. Three of Five studies assessing urinary incontinence (UI) reported no significant difference in UI, whereas two reported increased UI. All studies that looked at pelvic organ prolapse reported a higher incidence of symptomatic prolapse and reduced pelvic floor muscle strength in women with LAA + OASI compared with those without LAA.

Conclusion: Levator ani avulsion is prevalent following vaginal birth and is strongly associated with OASI. Incidence of AI does not increase in women with LAA and OASI, but they had greater symptom bother. OASI with LAA appears to increase the incidence of pelvic floor weakness and pelvic organ prolapse. There is no consensus agreement on the effect of LAA + OASI on UI.

Keywords: Anal incontinence; Fecal incontinence; Levator ani avulsion; Obstetrical anal sphincter injury; Pelvic floor dysfunction; Urinary incontinence.

Publication types

Review