The Association Between Levator Ani Integrity and Postpartum Ano-Rectal Dysfunction: A Systematic Review

Pregnancy and delivery are commonly associated with ano-rectal dysfunction. In addition, vaginal delivery may impact both the structure and functionality of the pelvic floor. Herein, we systematically reviewed the literature for the potential association between levator ani muscle (LAM) avulsion and ano-rectal function after childbirth.

We systematically searched the PubMed, EMBASE, CINAHL, Web of Science Core Collection, CENTRAL (Cochrane), Clinicaltrials.gov, and ICTRP databases from inception. We selected studies reporting on the anatomy of the LAM and ano-rectal function within 24 months after childbirth, the former determined by imaging and the latter measured through validated questionnaires or ano-rectal manometry. Meta-analyses were used to pool data from studies reporting on the association between LAM avulsion and ano-rectal function, with subgroup analysis according to the presence or absence of anal sphincter trauma. Summary odds ratio (OR) and mean difference (MD) are reported with 95% confidence intervals.

From the 7,621 studies identified, 11 were included, reporting on 2,146 women. Ten studies used transperineal ultrasound (TPUS) and one study used magnetic resonance imaging (MRI) for LAM assessment. Ano-rectal function was assessed through validated questionnaires in all but one study, in which ano-rectal manometry was used. There was no evidence for an association between LAM avulsion and symptoms of incontinence (OR 1.75 [0.74, 4.12]; MD 0.13 [-0.58, 0.85]), including in the subgroup of patients with concomitant anal sphincter injury (OR 1.83 [0.71, 4.71]).

We did not identify an association between LAM avulsion and ano-rectal dysfunction following vaginal childbirth.