The human autonomous karyotype and the origins of prenatal testing: children, pregnant women and early Down's syndrome cytogenetics, Madrid 1962-1975.

Through their ability to reveal and record abnormal chromosomes, whether inherited or accidentally altered, chromosomal studies, known as karyotyping, became the basis upon which medical genetics was constructed. The techniques involved became the visual evidence that confirmed a medical examination and were configured as a material culture for redefining health and disease, or the normal and the abnormal, in cytological terms. I will show that the study of foetal cells obtained by amniocentesis led to the stabilisation of karyotyping in its own right, while also keeping pregnant women under the vigilant medical eye. In the absence of any other examination, prenatal diagnosis by foetal karyotyping became autonomous from the foetal body. Although medical cytogenetics was practiced on an individual basis, data collected about patients over time contributed to the construction of population figures regarding birth defects. I study this complex trajectory by focussing on a Unit for Cytogenetics created in 1962 at the Clínica de la Concepción in Madrid. I incorporate the work and training of the clinicians who created the unit, and worked there as well as at other units in the large new hospitals of the national health care system built in Madrid during the mid-1960s and early 1970s.