Amniocentesis is generally used for prenatal diagnosis during the second trimester and involves inserting a special needle from the woman's abdomen into the amniotic fluid cavity. So-called gene-chip testing, also known as non-invasive DNA testing, is usually only used for one type of non-invasive DNA test and amniocentesis. If the gene chip is normal, it is almost certain that the fetus does not have a genetic disease. A microarray is a prenatal test, and high risk simply means that the baby has a high risk of developing the disease.