Interethnic variation in pelvic floor morphology in women with symptomatic pelvic organ prolapse

Introduction and hypothesis: There is a lack of epidemiological studies evaluating female pelvic organ prolapse in developing countries. Current studies have largely focused on women of white ethnicity. This study was designed to determine interethnic variation in pelvic floor functional anatomy, namely, levator hiatal distensibility and pelvic organ descent, in women with symptomatic pelvic organ prolapse in a multi-ethnic South African population. Methods: This prospective observational study included 258 consecutive women referred for pelvic organ prolapse assessment and management at a tertiary urogynaecological clinic. After a detailed history and clinical examination, including POPQ assessment, patients underwent a 4D transperineal ultrasound. Offline analysis was performed using 4D View software. Main outcome measures included levator muscle distensibility, pelvic organ descent, and levator ani defects (avulsion). Results: Mean age was 60.6 (range, 25–91) years, mean BMI 29.83 (range, 18–53). Points Ba and C were lower and the genital hiatus more distensible in black women (all p < 0.05). They were found to have greater hiatal area (p = 0.017 at rest, p = 0.006 on Valsalva) compared with South Asians and whites and showed greater pelvic organ mobility (all p < 0.05) than Caucasians on ultrasound. Levator defects were found in 32.2% (n = 83) of patients and most were bilateral (48.2%, n = 40), with significant interethnic differences (p = 0.014). Conclusion: There was significant variation in clinical prolapse stage, levator distensibility, and pelvic organ descent in this racially diverse population presenting with pelvic organ prolapse, with South Asians having a lower avulsion rate than the other two ethnic groups (p = 0.014).