Final answer:
The triple marker screen measures maternal serum levels of AFP, HCG, and estriol to screen for indications of possible fetal defects. It is typically performed during the second trimester of pregnancy. The quad screen is a similar screening test that combines the results from the triple marker screen with a blood test that measures inhibin-A.
Step-by-step explanation:
The triple marker screen is used for screening indications of possible fetal defects. It measures maternal serum levels of AFP (alpha-fetoprotein), HCG (human chorionic gonadotropin), and estriol. This screening is typically performed during the second trimester of pregnancy.
During the first trimester, a different screening called nuchal translucency screening is performed. The quad screen is a screening test that combines the results from the triple marker screen with a blood test that measures inhibin-A. This test is also performed during the second trimester. Therefore, the correct answer to your question is D) Quad screen.