[Improved prenatal diagnostic possibilities for congenital abnormalities and chromosomal disorders. Advantages and disadvantages of screening and diagnostic methods].

Significant progress has taken place in recent years regarding prenatal screening and diagnosis of severe foetal malformations and chromosomal disorders. This review describes blood sample screening in 15-16 week of pregnancy compared with the other prenatal examinations such as amniocentesis and chorionic villus sampling. Serological screening of all pregnant women based on a blood sample taken at 15-16 weeks of pregnancy would lead to identification of about 70% of the screened women having to undergo a conclusive investigation i.e. either a thorough ultrasound examination or an amniocentesis. This is compared with the present Danish prenatal program, where invasive examinations are carried out in about 13% pregnant women without a high detection rate for malformations and chromosome disorders. The Danish National Health Board has recently published new guidelines where the blood test is primarily offered to pregnant women over 34 years of age and not to all pregnant women as in many other countries.