Rethinking maternal AFP race adjustments
November 2024—David Grenache, PhD, D(ABCC), chief scientific officer of TriCore, is breaking no new ground when he considers the maternal serum alpha-fetoprotein test and says, “A screening test is designed to put people into one of two camps.” No scientific advances there. But the reverberations of this particular screening test have landed patients and physicians in complicated situations of late. The obvious divide is to identify increased risk of fetal abnormalities, including open neural tube defects. But the test has historically incorporated a race adjustment for Black patients. And that adjustment—seen as a way to account for reported differences in AFP values between Black and non-Black pregnant persons—in turn has come under more scrutiny recently as physicians question whether the adjustment should continue to be used, or whether it should be dropped, à la the race adjustment for eGFR/renal function. Compared with eGFR, evaluating the race adjustment in maternal serum AFP screening is more in its infancy, Dr. Grenache says.