[Prenatal diagnosis: uncertainties and perspectives].

The practice of faetal medicine has been regulated by law as of July 29th 1994, licensing Multidisciplinary Centres for Prenatal Diagnosis. With time passing by, echography has become more and more accurate, genetics and molecular biology further developed, prenatal diagnosis increasingly precocious and intrusive. Indications for medical interruption of pregnancy are easy to decide for obvious malformations. They become far more difficult when they concern a risk of disease or handicap often hazardous to quantify. Beneficial for the sake of individuals, prenatal diagnosis may happen to possibly appear collectively detrimental, as for the systematic screening for Down syndrome. Testing of faetal DNA, present in maternal serum since the early weeks of pregnancy, should in the near future outset antenatal invasive procedures and provide a useful alternative to pre implantation diagnosis.