Effect of anatomic urethral length on the correlation between the Q-tip test and descent at point Aa of the POP-Q system

The objective of this study is to evaluate the effect of anatomic urethral length on the relationship between descent at point Aa of the pelvic organ prolapse quantification (POP-Q) system and the Q-tip straining angle. The records of 323 patients who were evaluated for urinary incontinence were reviewed. Prolapse staging was performed using the POP-Q system. Urethrovesical junction hypermobility defined as a maximal straining angle ≥30° was assessed with the Q-tip test. Urethral length was measured with a urethral profilometer. A substantial correlation was found between descent at point Aa and the straining Q-tip angle (r=0.65, p<0.0001). There was no correlation between the anatomic urethral length and straining Q-tip angle (r=0.01, p=0.8). Urethral length does not affect the straining Q-tip angle. Point Aa is a strong predictor of an abnormal straining Q-tip angle in women with stage I anterior vaginal wall prolapse or greater.