Prenatal diagnosis in France.

Prenatal diagnosis (PND) is very developed in France, especially in the area of ultrasound (US) screening. The activity is regulated by law, and laboratories have to be authorized to perform any type of prenatal biological test if the purpose is to diagnose fetal defects. There are 70 cytogenetics laboratories and 50 biochemistry laboratories performing serum marker screening, about half of them being private. PND of chromosomal anomalies is offered to women over 37 years of age, to women who already had a child with a chromosomal anomaly, in case of abnormal US findings, if one of the parents has a balanced chromosomal anomaly and if the risk of chromosomal anomaly is higher than 1:250 according to the serum markers. Half of the trisomy 21 cases are now detected prenatally and pregnancies terminated. Fetal cell sampling is performed by amniocentesis in 70% of cases, by chorionic villus sampling in 7% of cases and by fetal blood sampling in 23% of cases. There are no professional guidelines and no quality assessment networks for any of the techniques in use. PND is regulated by two major laws: the Law on Abortion (1975) and the Law on Bioethics (1994).