Non-invasive screening of pregnant women with ultrasound early in pregnancy, combined with maternal blood analysis, has reduced the number of children born in Denmark with Down Syndrome by 50%, a scientist will tell the annual conference of the European Society of Human Genetics today.
Professor Karen Br'ndum-Nielsen, of the Kennedy Institute, Glostrup, Denmark, will say that another benefit of the introduction of this procedure in her country was a drop in the number of invasive pre-natal diagnostic procedures from 11% to approx. 6% of pregnancies.
In September 2004, Professor Br'ndum-Nielsen will tell the conference, the National Board of Health in Denmark recommended new guidelines for prenatal diagnosis. "Previously this was restricted to pregnant women over 35 years of age, but since the implementation of the new guidelines it has been available to any woman who wants it."
The women were offered a measurement of nuchal translucency in the fetus by ultrasound. This test looks at thickness of the black space (fluid) in the neck area of the fetus. If there is more than the normal amount of fluid the risk of Down syndrome is increased. Likewise if there is a certain combination of serum markers in the maternal blood test, taken at the same time, there is the possibility of an increased risk of a chromosomal abnormality. The combined screening is carried out at 11 to 14 weeks of gestation.