The association between different measures of pelvic floor muscle function and female pelvic organ prolapse.

introduction and hypothesisWe aimed to compare palpatory and translabial ultrasound (TLUS) measurements of pelvic floor muscle (PFM) function with symptoms and signs of female pelvic organ prolapse (FPOP) to determine a possible association.

methodsWe analysed data from 726 women with a mean age of 56 (SD 13.7, range 18-88) years, seen for symptoms of pelvic floor dysfunction between August 2011 and April 2013. The examination included a standardised interview and clinical assessment of FPOP with Pelvic Organ Prolapse Quantification (POP-Q) measurements, Modified Oxford Scale (MOS) grading and 4D TLUS.

resultsSymptoms of prolapse were reported in 51.4% (373 out of 726) with a mean bother score of 5.8 (SD 2.91, range 0-10). A clinically significant POP (Incontinence Society [ICS]-POP-Q stage ≥ 2) in any compartment was diagnosed in 77.1%. Mean MOS was 2.4 (SD 1.1, range 0-5). Significant POP on TLUS was seen in 54.6% (389 out of 712). TLUS volumes at rest and on maximal PFM contraction were analysed on a desktop PC, to assess the degree of bladder neck (BN) cranioventral shift and levator antero-posterior (AP) diameter reduction, blinded against other data. Mean cranioventral BN shift was 7.11 (SD 4.36, range 0.32-25.32) mm and mean levator AP diameter reduction was 8.6 (SD 4.8, range 0.3-31.3) mm. MOS was strongly associated with subjective and objective POP (P ≤ 0.001), whereas this was not true for TLUS measurements of tissue displacement.

conclusionThe MOS seems to be a more valid measure of PFM function than sonographically determined BN displacement or reduction of hiatal AP diameter observed on PFM contraction.