The Down-Syndrome-Evaluation or "Triple Test" is a blood examination for the identifica-tion of the individual risk for fetal chromosomal disorders or a neural tube defect ("open spine"). The main parameters for performing this "Triple Test" are PAPP-A and free beta-hCG for the first trimester screening (completed by the value of the nuchal translucency) or total hCG, unconjugated Estriol (uE3) and AFP (alpha-fetoprotein) for the second trimester screening.
In every pregnancy there is a small risk that the expected child has a chromosomal disor-der (e.g. Trisomy 21, Down-Syndrome). The older the mother the higher is this risk. Moth-ers who are 25 years old have a risk of 1:1300, for 30 years old mothers it is 1:900 and for 35 years it is 1:380. Pregnant women who are older than 35 years are offered a withdrawal of liquor amnii, in which the chromosoms of the unborn child are inspected for disorders (amniocentesis).
Performing a blood examination ("Triple test") also can determine the Down-Syndrome-Risk of pregnant women below the age of 35 years. If her risk is similar to the one of a woman at the age of 35 years or if it is even higher then the woman may get a chromoso-mal analysis using liquor amnii. The result of a Triple test will give a number for the risk of any mother for getting a child with chromosomal anomaly; this value may help her in the decision whether or not she needs the analysis of her liquor amnii. Finally it is only the chromosomal analysis giving definite results about chromosomal abnormalities of the ex-pected child, but unfortunately here exists a spontaneous abort risk of 1-2%.