Are screening tests for trisomy 21 compulsory?
These tests are certainly not compulsory. They are available to those who consider it important to have the information they can provide. It may be worthwhile for you to have such a test if it is important for you to know whether there is a risk of your unborn child carrying trisomy 21. You should also realize that, if the results are abnormal, the next step is amniocentesis in order to have a definite diagnosis.