Medical Genetics MSAFP screening is not a definitive test if the msafp test is low it suggests the risk of a Ds fetus equal to the risk of a woman age 35, and prenatal testing/chromosome studies are suggested if the parents want this informationMedical Genetics MSAFP screening is not a definitive test. If the MSAFP test is low it suggests the risk of a DS fetus equal to the risk of a woman age 35, and prenatal testing/chromosome studies are suggested if the parents want this information