No, the double marker test and NIPT are two completely different tests.. The Double Marker Test was first introduced in the mid-1990's and it checks the levels of two proteins in the mother's blood and tries to estimate the chances of the fetus having a chromosomal abnormality. In contrast, the NIPT is designed to isolate the fetus's DNA from the mothers blood, and directly checks this DNA for chromosomal abnormalities.. NIPT is a newer test, and since it directly checks the fetu's DNA it is more sensitive than the Double Marker Test.