Objective: There seems to be substantial variation in the prevalence of pelvic floor disorders between different ethnic groups. This may be due partially to differences in pelvic floor structure and functional anatomy. To date, data on this issue are sparse. The aim of this study was to compare hiatal dimensions, pelvic organ descent and levator biometry in young, healthy nulliparous Caucasian and African women.

Methods: Healthy nulliparous non‐pregnant volunteers attending a local nursing school in Uganda were invited to participate in this study during two fistula camps. All volunteers underwent a simple physician‐administered questionnaire and a four‐dimensional translabial ultrasound examination. Offline analysis was performed to assess hiatal dimensions, pelvic organ descent, levator muscle thickness and area. To compare findings with those obtained in nulliparous non‐pregnant Caucasians, we retrieved the three‐dimensional/four‐dimensional ultrasound volume datasets of a previously published study.

Results: The dataset of 76 Ugandan and 49 Caucasian women was analyzed. The two groups were not matched but they were comparable in age and body mass index. All measurements of hiatal dimensions and pelvic organ descent were significantly higher among the Ugandans (all P ≤ 0.01); however, muscle thickness and area were not significantly different between the two groups.

Conclusions: Substantial differences between Caucasian and Ugandan non‐pregnant nulliparae were identified in this study comparing functional pelvic floor anatomy. It appears likely that these differences in functional anatomy are at least partly genetic in nature.