[Chromosome abnormalities: known risk factors].

The high incidence of chromosomal anomalies at birth and the severity of the resulting handicap led to examining their detectability by amniocentesis. With current indications for amniocentesis, the detection rate did not excede 30%. Consequently, it seems necessary to estimate the importance of other known risk factors and to calculate the resulting impact this would have on eventually broadening the indications for amniocentesis. A review of the literature led the authors to discuss the relative importance of each known risk factor and its role in public health.