What is alpha-fetoprotein, and why’s my doctor screening for it?
The alpha-fetoprotein screening, or AFP screening, is a blood test that’s generally used to screen for the possibility of baby having a chromosomal disease (like Down syndrome) and neural tube defects (think spina bifida) by testing the mom-to-be’s blood for alpha-feto protein (AFP), a protein your baby produces. That’s because abnormally high or low levels of AFP could signal one or more of those problems.
Thing is, your doctor may never even mention the AFP screening to you. That’s because it’s usually done as part of the multiple marker screening (aka the triple, quad or integrated screen). Why exactly? Well, the AFP screen alone won’t likely give you an accurate prediction of baby’s risk of certain medical conditions, but when its results are combined with other lab tests, your doctor will get more, thorough, accurate information about baby’s risk at an earlier date.
Occasionally, AFP screening is used as a stand-alone test for women who have had chorionic villus sampling (CVS) early in pregnancy. CVS can accurately detect chromosomal abnormalities, but can’t detect neural tube defects. So an AFP test may be ordered to assess the risk of them.
The thing to remember with AFP screening (and all screenings) is that it merely suggests the possibility of certain medical conditions. If your AFP test indicates a higher-than-normal risk of a certain condition, your care provider will suggest additional testing (like an amniocentesis) to check for the presence of the disease.
Plus, more from The Bump:
Your Guide to Prenatal Tests and Checkups
Genetic testing basics?
What’s a multiple marker screening?