<prompt> Answer this question truthfullyWhat are the four components of a prenatal quad screen, and what do they measure?  <response>: <reason> The four components of a prenatal quad screen are alpha-fetoprotein AFP, human chorionic gonadotropin hCG, estriol, and inhibin A. These components are measured to assess the risk of certain fetal abnormalities, such as neural tube defects and Down syndrome. 