1 Introduction
Fetal growth restriction (FGR), traditionally defined as estimated fetal weight <10th percentile, is a leading risk factor for stillbirth and a major focus of antenatal ultrasound use.(1) Current diagnostic strategies for FGR perform poorly to predict perinatal morbidity and mortality, such that most fetuses diagnosed with FGR do not experience any perinatal morbidity.(2) Efforts have been made to customize fetal growth assessments using maternal and fetal factors that are associated with variation in fetal growth, including maternal race.(3) However, race is a socially defined construct that is fluid over time and subject to considerable admixture and therefore is a problematic proxy for genetic growth potential.(4) Furthermore, its use has the potential to exacerbate disparities by conflating the effect of imposed deprivations with genetics, potentially reclassifying abnormal growth as normal and causing necessary surveillance and interventions to be withheld.(5, 6)
Instead, the integration of genetic data may be a more valid and effective approach to personalize fetal growth assessments and thereby improve recognition of abnormal growth. Recent studies identified genetic markers associated with fetal growth that could be used for such purposes.(7-9) However, it is increasingly recognized that genetic findings in predominantly European cohorts do not generalize to more diverse populations.(10-12) Therefore, the objective of this study was to assess a genetic risk score (GRS) for birth weight (GRSBW), recently developed from a European cohort, for generalizability within groups defined by self-identified race and genetically predicted ancestry.
Because the rationale to use a GRSBW to customize fetal growth assessment is to obviate the impulse to customize using race/ethnicity, our secondary objective was to determine whether self-identified race/ethnicity remains associated with birth weight (BW) after accounting for the GRSBW.