Is compensatory thickening of puborectalis associated with severity of uterine prolapse postpartum?

Abstract

Abstract Background Uterine prolapse comprises the descent of the uterus into the vaginal canal due to weakened or damaged muscles and connective tissues such as ligaments, dramatically impairing women's quality of life. The primary aim of this study is to investigate the relationship between uterine prolapse and relevant factors, specifically measurements data obtained from pelvis Magnetic Resonance Imaging (MRI), as well as parameters derived from surface electromyography (sEMG) of the pelvic floor muscle (PFM). Methods In this retrospective study, 264 patients were allocated into one of three cohorts, including the non uterine prolapse group (NP), the mild uterine prolapse group (MP), and the moderate to severe uterine prolapse group (MSP). MRI was performed on all patients, and their puborectalis thickness (PRT) and uterus-pubococcygeal line (U-PCL) were annotated. sEMG recordings were used to capture fast-twitch stage maximum (FM) and slow-twitch stage average (SA). The study compared PRT, myoelectric parameters of pelvic floor muscle (PFM), and modes of delivery across all three sample groups, followed by a correlation analysis. Results Statistically significant variations were found in the left and right PRT and the two myoelectric parameters among the three prolapse groups (p<0.01). There was a weak correlation between left and right PRT and U-PCL (rl=0.377, Npl<0.01, rr=0.336, pr<0.01), as well as between the two myoelectric parameters and U-PCL (rf =-0.169, pf<0.01, rs=-0.203, ps<0.01). Differences in prolapse conditions based on distinct modes of delivery were statistically significant (χ2=12.067, p = 0.017). Conclusion It has been commonly observed that as the severity of prolapse increases, myoelectric values tend to decrease while the thickness of the puborectalis muscle increases. Uterine prolapse may result in damage to the puborectalis muscle, leading to compensatory thickening as well as a decrease in myoelectric strength of the pelvic floor muscle. Women who underwent painless labor were more likely to experience uterine prolapse.