The combined screening test is a risk free form of prenatal screening to search for an elevated chance of Down-, Edwards- or Pataus syndrome in your baby.
The test consists of two parts:
analysis of the mothers blood– between 9 and 14 weeks of pregnancy
measurement of the nuchal fold of the embryo- between 11 and 14 weeks of pregnancy
For the analysis of the mothers blood a sample will be drawn by the laboratory technician of SHO at Echo Amsterdam. This sample will then be sent to the VU medical centre for analysis of two substances made by the placenta. The concentration of these substances can be different in children with the aforementioned syndromes. The result of this analysis will not be given seperately but will be used to calculate the end result of the test.
Between 11 and 14 weeks an ultrasound scan will be made to measure the nuchal translucency in the embryos neck. This nuchal fold is filled with fluid in every embryo of this age. In children with one of the aforementioned syndromes this layer of fluid is often (much) thicker than in chromosomaly normal children. As far as possible this early in the pregnancy our ultrasound technician will also look for other anomalies of the embryo.
The results of the bloodanalysis and the measurement of the nuchal translucency will be combined with your age and the exact date of your pregnancy in a statistical program. The end result will be an estimate of the chance that your baby has Downs- Edwards- or Pataus syndrome. This test does not give certainty about the syndromes. If your result shows an elevated chance you will be given the choice to do further testing to obtain certainty, like NIPT, Chorionic Villus sampling (CVS) or Amniocentesis (AFT).