Screening test for open neural tube defects (detects 80% open spina bifida, 90% anencephaly), Down syndrome (detects 75% to 80%), and trisomy 18 (detects 73%).

AFP tetra is a screening test. A positive AFP tetra result means that more diagnostic testing may be offered to the pregnant woman to determine if a neural tube defect or chromosome abnormality is present.

Haddow JE, Palomaki GE, Knight GJ, Foster DL, Neveux LM. Second trimester screening for Down's syndrome using maternal serum dimeric inhibin A. J Med Screen. 1998; 5(3):115-119. PubMed 9795869