If both parents carry a mutation, newborns are at risk of classical CAH; therefore, the fetus may be tested for karyotype and CYP21A2 analysis (via chorionic villus sampling, amniocentesis, or cell-free fetal DNA testing, see below) to evaluate the subsequent risk of (1) adrenal insufficiency and (2) adrenal crisis, (3) hyperandrogenism, and subsequent (4) genital development abnormalities and (5) consideration of prenatal therapy. This evidence concerns the gene CYP21A2 and hyperandrogenism.