Gynecology World Conference 2026

Abstract

Bladder neck support is vital for urinary function, yet its assessment particularly during voiding remains challenging. Although transperineal ultrasound is reliable, it is not widely used, leading clinicians to rely on indirect measures such straining and pelvic floor muscle contraction are commonly used, though their relevance to voiding remains unclear.

Aims:
This study aimed to investigate whether bladder neck position during straining and pelvic floor muscle contraction predicts support during voiding.

Methods:
A prospective observational study included 30 asymptomatic women. Participants followed a standardised bladder filling protocol (~250 mL/hour for 3 hours, ~750 mL total), with bladder fullness confirmed before voiding. Transperineal ultrasound in the midsagittal plane visualised the symphysis pubis, urethra, bladder, vagina, and rectum. Bladder neck position was recorded at rest, during voiding (start, mid, and end), and during maximal straining and pelvic floor contraction after emptying. Primary outcomes were pubourethral angle (degrees) and symphysis pubis–bladder neck distance (mm). Displacement values were calculated relative to rest, and maximum mobility was defined as the difference between strain and contraction. Correlation analyses assessed relationships between bladder neck displacement during voiding and other tasks, as well as positional measures at end-void and end-task.

Results:
Pelvic floor muscle contraction resulted in bladder neck elevation, with negative pubourethral angle displacement in all but one participant and reduced symphysis-bladder neck distance in 77%. Straining caused bladder neck descent in 100% of participants, with 53% demonstrating increased symphysis-bladder neck distance. During voiding, movement was variable: most participants showed bladder neck descent, while approximately one-third demonstrated bladder neck elevation. No significant correlations were found between bladder neck displacement during voiding and displacement during straining or contraction. However, moderate to strong correlations were observed between bladder neck position at end-void and positions during other tasks.

Interpretation of results:

Bladder neck movement differed markedly between voiding, straining, and pelvic floor muscle contraction tasks. During natural voiding, both the angle of the pubourethral junction and the position of the bladder neck showed only small changes, indicating relatively limited movement. In contrast, voluntary straining produced a clear increase in the pubourethral angle, while the bladder neck itself remained largely in the same position. Conversely, maximal contraction of the pelvic floor caused a notable decrease in the pubourethral angle and a slight downward shift of the bladder neck.

When comparing the extremes of strain and contraction, the angular mobility of the bladder neck was substantial, whereas translational distance movement of the bladder neck to the inferior symphysis pubis point was minimal. Overall, changes in bladder neck angle were far more pronounced than changes in positional distance, and voiding-related movements were smaller than those induced by voluntary manoeuvres.

Conclusion:
Bladder neck behaviour during voiding is distinct and cannot be inferred from non-voiding tasks, highlighting the importance of direct assessment for accurate clinical evaluation. Suggesting that current measures in pelvic floor muscle tasks cannot act as surrogate indicators in voiding function