Objective: This study aims to evaluate the frequency of hydronephrosis and the effect of hydronephrosis on urodynamic parameters in patients with advanced-stage pelvic organ prolapse (POP).

Materials and Methods: This retrospective cross-sectional study was conducted between July 2019 - February 2020 with 66 patients who were admitted to the urogynecology outpatient clinic with symptomatic advanced-stage POP. Urinary system ultrasonography and urodynamic examination were performed on all patients before the operation. The severity of prolapse in the study population was evaluated using the POP-Q system. Urinary system ultrasonography was performed by radiologists. Demographic data, POP time, and urodynamic parameters were compared in hydronephrosis and non-hydronephrosis cases.

Results: The general frequency of hydronephrosis among the patients was 19.7% (13/66 patients). It was found that the weight (p= 0.0001) and body mass index (p= 0.004) levels were higher in patients with hydronephrosis. There was no significant difference in the duration of POP, the presence of detrusor overactivity, and other urodynamic parameters in patients with or without hydronephrosis.

Conclusion: There was no relationship found between hydronephrosis and urodynamic parameters. In line with these data, urinary system ultrasonography is recommended for all patients with POP due to the high frequency of hydronephrosis and the consequences of hydronephrosis leading to renal failure.