Natural history of levator ani muscle avulsion 4 years following childbirth

Abstract

Objectives The primary aim was to evaluate prospectively the natural history of levator ani muscle (LAM) avulsion 4 years following first delivery and its correlation with signs and symptoms of pelvic floor dysfunction (PFD). The secondary aim was to investigate the effect of a second vaginal delivery on the incidence of LAM avulsion and PFD. Methods This was a prospective longitudinal study of nulliparous women recruited antenatally, who were assessed at 36 weeks' gestation and 3 months, 1 year and 4 years postpartum for signs and symptoms of PFD and presence of LAM avulsion. Pelvic floor muscle strength was assessed by digital palpation, and pelvic organ prolapse (POP) was assessed using the POP quantification (POP‐Q) system. Validated questionnaires were used to evaluate urinary, bowel and sexual function and symptoms of POP. Transperineal ultrasound was performed to assess LAM integrity and hiatal biometry. Differences in signs and symptoms of PFD over time were evaluated using a linear mixed model, separately in women who had had one delivery and in those who had two or more deliveries during the study period. Results Of 269 women recruited, 147 (55%) attended the 4‐year follow‐up and were examined at a mean interval of 3.8 ± 0.4 years after their first delivery. Of these, 74 (50%) had a subsequent delivery. The prevalence of LAM avulsion 4 years after a first vaginal delivery was 13%, with no difference between women who had one and those who had two or more vaginal deliveries. Women with an intact LAM and one or more deliveries showed no change in signs and symptoms of PFD at 4 years compared with the previous assessments. Of women with one vaginal delivery who were diagnosed with LAM avulsion 3 months or 1 year postpartum, those in whom the LAM avulsion was no longer evident at 4 years (42%) showed worsening of POP‐Q measurements, whereas those with persistent LAM avulsion (58%) showed significant worsening in pelvic floor muscle strength and hiatal area on ultrasound. After a second vaginal delivery, no new avulsions were diagnosed, however, previous LAM avulsion became more extensive in 44% of women and hiatal area increased in women with persistent LAM avulsion. Conclusions The first vaginal delivery carries the greatest risk for LAM avulsion, with impact on signs of PFD 4 years later. A second vaginal delivery could result in deterioration of LAM avulsion, but no new avulsions were found. © 2020 International Society of Ultrasound in Obstetrics and Gynecology

Evaluation of Levator ani muscle injury in primiparous women at one and six week’s postpartum using 3D transperineal ultrasound: comparative Cohort study

“…Puborectalis avulsion was identified as a loss of continuity between the muscle and the pelvic sidewall with no muscle remaining (Figure 1) [15]. In this study the incidence of LAM avulsions and hematomas was 16.6% at the first visit, which was lower than those detected by Van Gruting et al, which was 21% [16]. The incidence of LAM avulsions which were observed by Iva Urbankova et al at 1 year follow up was 27.1% in total.…”

Levator ani muscle avulsion and subsequent vaginal delivery: 8‐year longitudinal follow‐up

“…A pooled avulsion rate of 15% in primiparous women after vaginal delivery has been estimated in a systematic review including 37 studies 32 . Still, only a few groups have assessed LAM avulsion after subsequent delivery 17,18,33 . In our study, the proportion of women with avulsion 8 years after first delivery was higher compared to follow-up 1 year after the first delivery in women with subsequent vaginal delivery.…”

The relationship between pelvic floor functions and vaginal microbiota in 6–8 weeks postpartum women

“…Pressure from the growing uterus during pregnancy, decreased collagen fibers, and damaged myofibrils had adverse effects on pelvic floor muscle functions. Especially during vaginal delivery, the vaginal walls and introitus were overstretched, and levator ani muscle (LAM) was subjected to extensive stretch even tear, weakening the support for pelvic organs support and leading to vaginal laxity ( Manzini et al, 2020 ; Fu et al, 2021 ; Van Gruting et al, 2021 ). The vagina was unable to maintain closed, and the mucosal folds became flattened because of excessive extension, leading to weakened mucosal barrier.…”