First steps in antenatal diagnosis, 1956

The original observation by the Canadians Barr and Bertram (Nature 163:676-677, 1949), that the nuclei of female cells from several species contained a small body, the sex chromatin, opened the possibility of sex determination in human epithelial and haematological cells. 7 years later it further led to the scientific question, whether or not human amniotic cells were sufficiently well-preserved and numerous that they could form the basis for a reliable sex diagnosis of the human fetus. A technical condition was to test the safety and reliability of the physical access to the amniotic cavity, which needed co-operation between geneticists and obstetricians. The article describes the first Danish steps in 1956 that led to the subsequent success of antenatal diagnosis as part of clinical genetics.