Multicenter study of the evolution of different types of avulsion over the 12 months after delivery

OBJECTIVE: To perform a multicenter study of muscle recovery in levator ani muscle (LAM) avulsion during the first 12 months postpartum according to the type of LAM avulsion suffered. METHODS: This was a multicenter prospective observational study including 242 primiparas. Transperineal ultrasound was performed at 6 months and 12 months after delivery. Type I LAM avulsion was present when most of the lateral fibers of the pubovisceral muscle were observed at the muscle's insertion at the pubic level. Type II LAM avulsion was defined as complete detachment of the pubovisceral muscle from its insertion at the pubic level. RESULTS: Among the 56 patients who completed the study (with ultrasound at 6 and 12 months after delivery), 76 avulsions (10 cases of bilateral avulsion) were identified at 6 months after delivery, and the total number of avulsions had decreased to 58 at 12 months after delivery (P < 0.001; 95% confidence interval [CI] 13.9%–33.5%). This decrease was due to the disappearance of 69.2% of the cases of Type I LAM avulsions (P < 0.001; 95% CI: 50.2%–88.2%). However, the number of Type II LAM avulsions remained constant at 6 months and 12 months after delivery. CONCLUSION: The spontaneous resolution of LAM avulsion during the first 12 months postpartum occurs in cases of Type I LAM avulsion but is not observed in Type II LAM avulsion.