Morphological changes after pelvic floor muscle training measured by 3-dimensional ultrasonography: a randomized controlled trial.

OBJECTIVE To investigate morphological and functional changes after pelvic floor muscle training in women with pelvic organ prolapse. METHODS This randomized controlled trial was conducted at a university hospital and a physical therapy clinic. One hundred nine women with pelvic organ prolapse stages I, II, and III were randomly allocated by a computer-generated random number system to pelvic floor muscle training (n=59) or control (n=50). Both groups received lifestyle advice and learned to contract the pelvic floor muscles before and during increases in intraabdominal pressure. In addition the pelvic floor muscle training group did individual strength training with a physical therapist and daily home exercise for 6 months. Primary outcome measures were pelvic floor muscle (pubovisceral muscle) thickness, levator hiatus area, pubovisceral muscle length at rest and Valsalva, and resting position of bladder and rectum, measured by three-dimensional ultrasonography. RESULTS Seventy-nine percent of women in the pelvic floor muscle training group adhered to at least 80% of the training protocol. Compared with women in the control group, women in the pelvic floor muscle training group increased muscle thickness (difference between groups: 1.9 mm, 95% confidence interval [CI] 1.1-2.7, P<.001), decreased hiatal area (1.8 cm, 95% CI 0.4-3.1, P=.026), shortened muscle length (6.1 mm, 95% CI 1.5-10.7, P=.007), and elevated the position of the bladder (4.3 mm, 95% CI 2.1-6.5, P<.000) and rectum (6.7 mm, 95% CI 2.2-11.8, P=.007). Additionally, they reduced the hiatal area and muscle length at maximum Valsalva indicating increased pelvic floor muscle stiffness. CONCLUSION Supervised pelvic floor muscle training can increase muscle volume, close the levator hiatus, shorten muscle length, and elevate the resting position of the bladder and rectum. CLINICAL TRIAL REGISTRATION www.clinicaltrials.gov, NCT00271297. LEVEL OF EVIDENCE I.