[Anthropometric and densitometric investigations into the prenatal development of the human pelvic bone].

The aim of this work was to study the prenatal development and mineralization of ossification centres (OC) in the pelvic bone (ilium, ischium, and pubic bone) using radiography and optical density measurements. The material consisted of 90 human fetuses (29 males and 61 females) with a gestational age of 12 to 28 weeks. Both pelvic bones were obtained and radiographs directed at OC were taken. Analysis was done with a computer after digitalization of the radiographs. The area of each OC was determined. With prior standardisation, optical density of the radiographs was measured and mean density was calculated for each OC. OC appear in the ischium between week 12 and 16 and in the pubic bone between week 19 and 24 of gestation. The pelvic bone does not demonstrate sexual differences during prenatal development. Anthropometric findings regarding OC of the pelvic bone correlated positively with fetal age. The dynamics of OC formation varies, being fastest in the case of ilium in the direction from acetabulum to extension of the anterior margin of greater sciatic notch. The mineral density of the pelvic bone increases with age and the mineralization rate changes throughout fetal life.