Demographic features of female urethra length.

Aims: To determine cohort urethral length, identify epidemiological factors influencing the parameter and to establish the percentage of cases with clinically relevant outsized urethras.

Methods: Prospective cohort study conducted in two tertiary clinical centers between 2013 and 2017. Nine hundred and twenty seven consecutive adult, Caucasian females attending outpatients' clinics were included. The urethral length has been measured in pelvic floor ultrasound examination. The exclusion criteria were inadequate bladder filling (<200 mL; >400 mL), previous history of pelvic floor surgery, and no consent.

Results: Urethral length varied from 19 to 45 mm. The distribution of the examined parameter was normal. Obese patients had significantly longer urethras as compared to non-obese subjects. Number of vaginal deliveries was connected with shorter urethral length. The limitations of the study are: analysis only of Caucasian patients and subjects without previous pelvic floor surgeries.

Conclusions: Differences in urethral length in the female population were demonstrated. Thirty percent of patients have atypical urethras that may be a risk factor for sling surgery failure. We therefore postulate introduction of urethral measurement before the procedure.