Reconsidering Race Adjustment in Prenatal Alpha-Fetoprotein Screening

Area of Science:

• Obstetrics and Gynecology
• Prenatal Diagnostics
• Biochemistry

Background:

• Maternal serum alpha-fetoprotein (AFP) screening is a key component of prenatal diagnostics.
• Current guidelines recommend race-based adjustments for Black individuals in AFP screening.
• The scientific basis for this race-based adjustment requires reevaluation.

Purpose of the Study:

• To reevaluate the relationship between maternal race and maternal serum AFP values in prenatal screening.
• To determine if race-based adjustments are necessary for accurate AFP interpretation.

Main Methods:

• A single-center retrospective analysis of 27,710 patients undergoing prenatal screening (2007-2020).
• Creation of nomograms for raw maternal serum AFP values by gestational age.
• Multivariable linear regression models to assess the impact of gestational age, maternal weight, and race on AFP levels.

Main Results:

• No significant difference in raw maternal serum AFP values was observed between Black and non-Black patients (P=.065).
• After adjusting for gestational age and maternal weight, no difference in AFP levels was found between racial groups (P=.81).
• Black patients had slightly later mean gestational age at blood draw and higher mean maternal weight.

Conclusions:

• Maternal serum AFP values do not differ between Black and non-Black individuals when adjusted for key clinical factors.
• The findings challenge the necessity of routine race-based adjustments in prenatal AFP screening.
• Discontinuation of race-based adjustments for maternal serum AFP screening is suggested.