Pelvic organ prolapse in Caucasian and East Asian women: a comparative study

Ethnicity has been suggested to be a significant risk factor for pelvic organ prolapse (POP); yet, pelvic organ descent in different ethnic groups, especially in Asian populations, is not well studied. The aim of this study was to compare prolapse stages, pelvic organ descent and hiatal dimensions between East Asian and Caucasian women presenting with symptoms of POP.

This was a prospective observational study of East Asian and Caucasian women presenting with symptoms of POP to a tertiary urogynecology clinic in, respectively, Hong Kong and Sydney. Demographic data, prolapse symptoms and prolapse stage were assessed. Physical examination was performed using the pelvic organ prolapse quantification (POP-Q) system. All women underwent transperineal ultrasound using Voluson systems. Offline analysis of four-dimensional ultrasound volume data was performed at a later date, by one operator blinded to all clinical data, to ascertain pelvic organ descent and hiatal dimensions on Valsalva maneuver. Levator muscle avulsion was assessed in volumes obtained on pelvic floor muscle contraction. Multiple logistic regression analysis was performed to assess factors associated with prolapse on clinical and ultrasound examinations.

A total of 225 East Asian women were included between July 2012 and February 2014 from the Hong Kong clinic and 206 Caucasian women between January 2015 and July 2016 from the Sydney clinic. There was no significant difference in the overall staging of prolapse. However, in East Asian women, compared with Caucasians, apical compartment prolapse was more common (99.6% vs 71.8%, P < 0.001) and posterior compartment prolapse less common (16.9% vs 48.5%, P < 0.001) on POP-Q examination. On Valsalva maneuver, the position of the uterus was lower in East Asian than in Caucasian women (-11.3 vs 1.35 mm, P < 0.001), while the rectal ampulla position was lower in Caucasians than in East Asians (-10.6 vs - 4.1 mm, P < 0.001). On multiple regression analysis, Caucasian ethnicity was a significant factor for lower risk of apical compartment prolapse on clinical assessment (odds ratio (OR), 0.01; P < 0.001) and on ultrasound (OR, 0.13; P < 0.001), and for a higher risk of posterior compartment prolapse on clinical assessment (OR, 4.36; P < 0.001) and of true rectocele on ultrasound (OR, 8.14; P < 0.001).

East Asian women present more commonly with uterine prolapse while Caucasians show more often posterior compartment prolapse. Ethnicity was a significant predictor of type of prolapse on multivariate analysis. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.