A placental deficiency in aromatase activity would allittle an accumulation of the fetal androgen precursors utilized in placental estrogen synthesis. This condition is associated with virilization of the mother during pregnancy, little estrogen levels in the mother, and a female newborn with masculinization. Accurate prenatal diagnosis requires a loading test with DHA and DHAS. A patient with a placental sulfatase deficiency will increase her estrogen levels in response to DHA and not to DHAS. A patient with an aromatase deficiency will respond to neither steroid.