Levator muscle avulsion and subsequent vaginal delivery: longitudinal 8-year follow-up.

Abstract

The aim of this study is to assess the evolution of levator avulsion from 1 year to 8 years after first delivery in women with subsequent vaginal deliveries compared to women without subsequent vaginal deliveries. Further, we aim to assess whether women with full and partial avulsion 8 years after first delivery have larger levator hiatus area and more symptoms of pelvic organ prolapse compared to women with normal levator insertion. In this single center longitudinal study 195 initially primiparous women were included and underwent transperineal ultrasound 1 year and 8 years after first delivery. Muscle insertion was assessed by tomographic ultrasound imaging in the axial plane. Full levator avulsion was defined as abnormal muscle insertion in all three central slices. Partial levator avulsion was defined as abnormal muscle insertion in one but less than three central slices. Eight years after first delivery levator hiatus area was assessed at rest, during maximum pelvic floor muscle contraction, and maximum Valsalva maneuver. To assess symptoms of pelvic organ prolapse the vaginal symptoms module from the International Consultation on Incontinence Questionnaire was used. At 1 year follow-up, 25 women (12.8%) showed signs of avulsion, 20 women fulfilled sonographic criteria for full avulsion and 5 women fulfilled sonographic criteria for partial avulsion. Eight years after first delivery, 35 (17.9%) women were diagnosed with avulsion, of them 25 women were diagnosed with full avulsion and 10 women were diagnosed with partial avulsion. No women with partial and full avulsion at 1 year improved on their avulsion status at 8-year follow-up. In the subsequent vaginal delivery group, 21 women (14%) were diagnosed with partial and full levator avulsion 1 year after first delivery, and 31 women (20.7%) were diagnosed with partial and full avulsion 8 years after first delivery. Of the 45 women without subsequent vaginal delivery, one woman with partial avulsion 1 year after first delivery was diagnosed as full avulsion at 8-year follow-up. All women with full avulsion at 1-year follow-up were diagnosed as full avulsion at 8 years regardless of subsequent vaginal delivery. At 8-year follow-up women with full avulsion had statistically significant larger levator hiatus area compared to women with normal muscle insertion. Vaginal symptoms scores ranged between 5.5 (SD 5.7) and 6.0 (SD 4.0) and vaginal symptom quality of life scores ranged between 0.9 (SD 1.4) and 1.5 (SD 2.2) and did not differ statistically significantly between women with normal muscle insertion and women with partial and full avulsion at 8-year follow-up. More avulsions 8 years after first delivery compared to one year after first delivery were found in women with subsequent vaginal delivery. Except one primipara, none of the women without subsequent vaginal delivery changed on their levator status from 1 to 8 years after first delivery. Larger levator hiatus area was found in women with full avulsion compared to women with normal muscle insertion at 8-year follow-up. Vaginal symptoms scores were low and did not differ between women with normal muscle insertion, partial and full avulsion at 8-year follow-up. This article is protected by copyright. All rights reserved.