[Changes in pelvic anatomy in 8 decades--computerized tomography study of obstetrically relevant pelvic measurements]

An increasing proportion of obstetric operative procedures due to cephalopelvic disproportion gave raise to the question, whether there has been a change in pelvic anatomy during the past decades. In a retrospective evaluation of 467 computerized pelvic tomograms of patients aged between 18 and 88 years relevant parameters of pelvic proportion were determined. As these parameters are not subject to age-conditioned changes, the values may be viewed as representative for the time of patients' birth or fertility period respectively. Changes in pelvic anatomy turned out to be complex: The transverse elliptic shape of pelvic inlet changed into sagittal elliptic form, the pelvic midplane is contracted progressively, sacral concavity is reduced. Obviously, this obstetrically adverse development is influenced by the fact, that unfavourable pelvic conformation can be transmitted more intensively by the generous indication for cesarean section. This development is contrasted by the circumstance of fetal acceleration. Therefore, an increase in cephalopelvic disproportion has to be expected. For the sake of a safe obstetrical management in these situations the generous use of ante partum pelvimetric diagnosis seems to be advisable.