Which of the following is not quantified in the triple test for Down syndrome?

The correct choice indicates progesterone is not quantified in the triple test for Down syndrome. The triple test, typically performed during the second trimester of pregnancy, is designed to assess the risk of chromosomal abnormalities, including Down syndrome (trisomy 21). The markers that are measured in the triple test include alpha-fetoprotein (AFP), unconjugated estriol (uE3), and human chorionic gonadotropin (hCG).

Alpha-fetoprotein is a protein produced by the fetal liver, and its levels can indicate the risk of certain congenital abnormalities. Unconjugated estriol is an estrogen produced by both the fetal liver and the placenta, and its levels can indicate fetal well-being. Human chorionic gonadotropin is a hormone produced during pregnancy, and its levels can vary with certain types of chromosomal abnormalities.

Progesterone, on the other hand, is a hormone primarily involved in the regulation of the menstrual cycle and maintenance of early pregnancy, but it does not provide pertinent information regarding the risk of Down syndrome or other chromosomal disorders in the context of the triple test. Therefore, its quantification is not part of this specific screening test.