Relationship between female sexual function, vaginal volume, vaginal resting tone, and pelvic floor muscle strength in women with stress urinary incontinence

Vaginal morphology and pelvic floor muscle (PFM) strength may influence sexual stimulation, sensation, and orgasmic response. This study aimed to determine the relationship between female sexual function and PFM strength and vaginal morphology (represented by vaginal resting tone and vaginal volume) in women with stress urinary incontinence (SUI). Forty-two subjects with SUI were recruited for the study. Female sexual function was measured using the female sexual function index (FSFI) questionnaire. PFM strength was measured by digital palpation. Vaginal resting tone (mmHg) and vaginal volume (mL) were measured using a perineometer. The significance of the correlations between female sexual function and PFM function and hip muscle strength was assessed using Pearson's correlation coefficients. If a significant correlation between vaginal morphology and FSFI score was confirmed using Pearson's correlation, the cutoff value was confirmed through a decision tree. PFM strength was significantly correlated with desire (r=0.397), arousal (r=0.388), satisfaction (r=0.326), and total (r=0.315) FSFI scores. Vaginal resting tone (r=-0.432) and vaginal volume (r=0.332) were significantly correlated with the FSFI pain score. The cutoff point of vaginal resting tone for the presence of pain-related sexual dysfunction was >15.2 mmHg. PFM strength training should be the first strategy to improve female sexual function. Additionally, because of the relationship between vaginal morphology and pain-related sexual dysfunction, surgical procedures to achieve vaginal rejuvenation should be carefully considered.