Comparison of transperineal ultrasound with POP-Q for assessing symptoms of prolapse

Our aim was to study any correlation between pelvic organ prolapse quantification (POP-Q) and ultrasound measurement of prolapse in women from a normal population and to identify the method with a stronger association with prolapse symptoms.

A cross-sectional study of 590 parous women responding to the Pelvic Floor Distress Inventory was carried out. They were examined using POP-Q and transperineal ultrasound, and correlation was tested using Spearman's rank test. Numerical measurements and significant prolapse (POP-Q ≥ 2 in any compartment or bladder ≥10 mm, cervix ≥0 mm or rectal ampulla ≥15 mm below the symphysis on ultrasound) were compared in symptomatic and asymptomatic women (Mann-Whitney U and Chi-squared tests).

A total of 256 women had POP-Q ≥ 2 and 209 had significant prolapse on ultrasound. The correlation (r_s) between POP-Q and ultrasound was 0.69 (anterior compartment), 0.53 (middle), and 0.39 (posterior), p < 0.01. Women with a "vaginal bulge" (n = 68) had greater descent on POP-Q and ultrasound in the anterior and middle compartments than asymptomatic women, p < 0.01. For women with a symptomatic bulge, the odds ratio was 3.8 (95% CI 2.2-6.7) for POP-Q ≥ grade 2 and 2.4 (95% CI 1.4-3.9) for prolapse on ultrasound. A sensation of heaviness (n = 90) and incomplete bladder emptying (n = 4) were more weakly associated with ultrasound (p = 0.03 and 0.04), and splinting (n = 137) was associated with POP-Q Bp, p = 0.02.

POP-Q and ultrasound measurement of prolapse had moderate to strong correlation in the anterior and middle compartments and weak correlation in the posterior compartment. Both methods were strongly associated with the symptom "vaginal bulge," but POP-Q had a stronger association than ultrasound.