Predictive Value of Pelvic Floor Muscle Morphometry Using 3D/4D Ultrasound in Relation to the Success of Pelvic Floor Muscle Training in Women with Stress Urinary Incontinence

The aim of our study was to establish the predictive value of pelvic floor muscle morphometry using 3D/4D ultrasound in relation to the success of pelvic floor muscle training (PFMT) for 12 weeks in women with stress urinary incontinence (SUI). A total of 86 women with SUI from regional gynaecological and urological outpatient clinics were enrolled on this cross-sectional study. SUI symptoms were assessed by the International Consultation on Incontinence Questionnaire (ICIQ-UI SF). Pelvic floor muscle function was evaluated using a perineometer. Pelvic floor muscle morphometry (PFMM) was evaluated by the size of the urogenital hiatus (HA in cm(2)) at rest (R), at contraction (C) and during the Valsalva manoeuvre, i.e., a strong push (V), by 3D/4D USG. The intervention was PFMT for 12 weeks. After PFMT, we noted significant improvement in SUI symptoms, pelvic floor muscle function and morphometry. Moderately significant (0.001) negative correlations were confirmed between the total ICIQ-UI SF score and strength (−0.236 **) and endurance (−0.326 **) of the maximal voluntary contraction (MvC), the number of MvC lasting 3 s (−0.406 **) and 1 s (−0.338 **). Moderately significant (0.001) positive correlations were confirmed between the total ICIQ-UI SF score and R (r = 0.453 **), C (r = 0.533 **) and V (r = 0.442 **). The predictive value of PFMM reached a positive prediction of a decrease with an ICIQ-UI SF score below 8. HA during V was most strongly associated with SUI reduction, with an area under the curve (AUC) of 0.87 (p ≤ 0.001), a positive predictive value of 83.3%, a negative predictive value of 75.0%, sensitivity of 78.9% and specificity of 80.0%. The predictive values of pelvic floor muscle morphometry using 3D/4D USG confirmed the success of PFMT in women with SUI.