OBJECTIVE: To determine the influence of intraabdominal pressure in the ultrasonographic evaluation of the urethrovesical junction (UVJ) and proximal urethra (PU) in patients with stress urinary incontinence (SUI). MATERIALS AND METHODS: A prospective, cross-sectional study was conducted at the Urinary Incontinence Research Unit of "Universidade Federal de Pernambuco", Brazil, from January 2002 to January 2005. Perineal ultrasounds of the UVJ and PU were performed in thirty-six women complaining of SUI with the bladder virtually empty (< 50 ml); simultaneous measurement of the intraabdominal pressure was also performed. An ultrasound machine with a computer chip and a high-resolution photographic camera connected to a 7 MHz vaginal probe was used for the evaluation. In order to measure the intraabdominal pressure, an urodynamic equipment with a 10fr rectal catheter connected to a pressure sensitive balloon was used. RESULTS: The age of the patients ranged from 25 to 69 years (mean 46.4 ± 10.2 years). On Valsava maneuver, the intra-abdominal pressure ranged from 7 to 193 cmH2O (mean: 99.3 ± 51.8 cmH2O; median: 99.5 cmH2O). Eight out of 31 (25.8%) patients with UVJ hypermobility had an intraabdominal pressure lower than 60 cmH2O. There was no statistically significant association between intraabdominal pressure and the ultrasound parameters studied. CONCLUSION: There is a specific urethral pressure index for each woman with SUI. However, there is no significant association between increase in intraabdominal pressure and increase of UVJ and UP hypermobility in women with clinical SUI.

Keywords: Stress urinary incontinence, Abdominal pressure, Perineal ultrasound, Urethrovesical junction