Patient's question:
Female, 25 years old, first pregnancy.Doctor's answer:
Alpha-fetoprotein (AFP), abbreviated as AFP, is a special protein synthesized by fetal liver cells and normally present in fetal serum. When AFP levels in a pregnant woman's serum are abnormally low, it should be considered that the pregnant woman may be carrying a child with Down syndrome.hCG is a protein hormone produced by trophoblast cells of the placental chorion that promotes gonadal development. It consists of two peptide chains (or subunits): α and β. When hCG levels in a pregnant woman's serum are abnormally high, it should be considered that the pregnant woman may be carrying a child with Down syndrome.
Down syndrome screening uses a dual serum marker of AFP and hCG as screening indicators. Specifically, if AFP ≤ 0.77 MoM and hCG ≥ 2.5 MoM are concurrently associated, it meets the high-risk diagnostic criteria for Down syndrome. At this point, the combined risk rate for Down syndrome is: P ≥ 1/270.
Neural tube defects (NTD) AFP