Used to evaluate chromosomal abnormalities
Evaluates MSAFP, estriol, β-HCG, inhibin A
Performed in the 2nd trimester
Diagnosis:
Down's syndrome Increased inhibin A, β-hCG
Low MSAFB, low estriol
Edward's syndrome (Trisomy 18)
Low MSAFB, estriol, beta-HCG, inhibin A
Notes:
Newer tests utilize Pregnancy-Associated Plasma Protein A (PAPP-A) , ultrasound determined nuchal transparency (measure of fluid in fetal neck) and free β-HCG
