Comparison of pelvic floor morphometry in supine and standing in women with and without pelvic organ prolapse: A cross-sectional exploratory study

Introduction:

Intra-abdominal pressure (IAP) and gravity may both challenge pelvic organ support and contribute to the development or worsening of pelvic organ prolapse (POP). This study aimed to assess whether pelvic floor morphometry differs between supine and standing positions in women with and without POP, at rest and with elevated IAP, and to compare the change in measures from the supine to standing position between groups.

Methods:

Thirty premenopausal vaginally parous women with ($n=15$) and without ($n=15$) POP were included. Transperineal ultrasound was used to assess pelvic floor morphometry (bladder neck [BN], rectal ampulla [RA], levator plate angle [LPA], anorectal angle [ARA], levator anteroposterior distance [LAP], and levator hiatal area [LHA]) in supine and standing, at rest and bearing down. Measures were compared between positions (supine and standing) and groups (women with and without POP).

Results:

At rest, BN and RA were lower and LPA was smaller in standing than supine for all participants (all $p<0.04$), and LHA and LAP distance were greater in standing than supine for women with POP ($p<0.001$). In standing rest, BN and RA were lower and LHA was greater in women with than without POP ($p<0.001$). There were no differences between women with and without POP in these measures in supine (all $p>0.23$). ARA was greater in women with POP than without POP in both positions at rest ($p=0.002$). During bearing down, BN and RA were lower, ARA and LPA were smaller, and LHA and LAP distance were larger in standing than in supine for all participants (all $p<0.023$). In bearing down in both positions, BN and RA were lower and ARA and LHA were greater in women with than without POP (all $p=0.013$).

Conclusion:

Our findings indicate lower pelvic floor support in women with POP compared to women without POP that is evident during bearing down in supine, and at rest and during bearing down in standing. These findings underscore the utility of transperineal ultrasound to assess pelvic floor morphometry in standing to guide management of women with POP.