The considerable development, during the last few years, of the antenatal diagnosis of congenital abnormalities is due to progress in cytogenetics but also to rapid improvements in obstetrical ultrasonography. With high-resolution ultrasound scanners, various interventions performed increasingly early during pregnancy can be guided with an ever decreasing risk. Thus, genetic diseases can now be detected at a very early stage by chorion biopsy combined with genetic engineering, and direct foetal blood sampling with a needle guided by ultrasound increases our knowledge of foetal physiology and provides an access to antenatal pathology. In the forthcoming years a true antenatal medicine will no doubt develop, no longer to eliminate foetuses, but to treat and cure them.