Cephalopelvic disproportion is common among Africans and is a major cause of maternal and perinatal mortality and morbidity. As the dimensions of the pelvis may vary between populations and according to stature and age, they need to be considered during childbirth and also in the planning and performance of pelvic and perineal procedures. The aim of this study was to assess the possible variations in the dimensions of the intact pelvic canal in South Africans and their implications. Eighty intact cadaver pelves, belonging to 40 white South Africans (20 males and 20 females) and 40 black South Africans (20 males and 20 females) were used for both metric and geometric morphometric analyses. Pelvic inlet shapes did not differ significantly between groups but pelvic inlet and midpelvic dimensions were the greatest in whites and females. The pubic symphyseal length was the greatest in whites and males and the smallest in black females, resulting in a smaller pelvic cavity anteriorly than for white females. Pelvic outlet shapes varied significantly between sexes in white South Africans and between populations in males. Females presented with the greatest dimensions. Black females presented with an elongated anteroposterior outlet diameter. Certain transverse pelvic diameters correlated positively with age in white males and with height in females. In planning childbirth options, the smaller pelvic inlet of black females and stature-dependent diameters should be considered. Pelvic and perineal 1 surgery may be technically more challenging because of smaller pelvic dimensions in black South Africans, especially in males.

Objective. To explore the relationship between pelvic floor thickness and bony pelvic outlet, in nulliparous and multiparous women of black and white South African (SA) ethnic group groups. Design. Quantitative retrospective analysis of computerised tomography (CT) scans. Setting. Academic Hospital and University in Pretoria, SA. Population/sample. Black and white women of SA ethnic groups. Methods. A total of 125 CT scans were sampled from a tertiary hospital in Pretoria South Africa, where 50 belonged to SA white women and 75 to SA black women. The data was reconstructed with Mevislab software to measure pelvic floor thicknesses and bony parameters. Statistical analyses were performed using Paleontological Statistics Comparisons (PAST). Main outcome measures. Variations were observed in pelvic floor thicknesses and bony parameters measured in SA women, which varied according to ethnic group, age and parity. Results. Greater bony dimensions (except anteroposterior pelvic outlet) were found in white compared to black women. A thicker pelvic floor was noted in black compared to white women. Some bony dimensions increased with parity. Pelvic floor thickness became thinner with increasing parity and age in both ethnic groups. Conclusion. There existed an interethnic variation in pelvic floor thickness and bony dimensions, where white women presented with thinner pelvic floor and greater bony pelvic dimensions when compared to black women.