What specialized diagnostic test involves taking a blood sample from the mother to screen for conditions like spina bifida?

The correct answer is AFP (Alpha-Fetoprotein Screening) because this test specifically measures the level of alpha-fetoprotein, a substance produced by the developing fetus that can be detected in the mother's blood. This screening is primarily used to assess the risk of certain conditions, such as spina bifida and other neural tube defects, as well as Down syndrome and other chromosomal abnormalities.

AFB screening is a non-invasive test and does not involve taking fluid from the uterus or any direct sampling of fetal tissue, which distinguishes it from other tests like amniocentesis and CVS, both of which require more invasive procedures.

While amniocentesis and CVS provide more definitive information about genetic conditions by analyzing the genetic material or fluid, they are not specifically aimed at screening for conditions like spina bifida through a simple blood test. Nuchal Translucency (NT) is a different type of screening that focuses on measuring fluid at the back of the baby's neck during an ultrasound, which is not a blood test either. Thus, among the choices, AFP is uniquely identified for its role in screening for spina bifida through a blood sample from the mother.