Racial/ethnic-derived maternal diets predict birth outcomes better than a diet derived from a combined sample among Hispanic/Latina and non-Hispanic White pregnant individuals in the ECHO Cohort.

Little is known about diet based on maternal fasting blood glucose (FBG) and birth outcomes in diverse populations. We hypothesized that racial/ethnic-derived FBG-based diets would predict birth outcomes better than a diet derived from the overall sample. Pregnant Hispanic/Latina (n = 420) and non-Hispanic White (n = 564) individuals (combined, n=984) from two Environmental influences on Child Health Outcomes (ECHO) cohorts provided ≥ 1 24-h diet recalls. We evaluated primary (birthweight [BW]-for-age, macrosomia, large-for-gestational age, and preterm birth) and secondary (BW, gestational age [GA] at birth, low birthweight (LBW), and small-for-gestational age) birth outcomes. Reduced-rank regression with maternal FBG was used to derive dietary patterns in the combined and racial/ethnic samples. We used multivariable linear and logistic regression to estimate diet associations with birth outcomes. In each racial/ethnic group, seemingly unrelated estimation with clustering was used to test differences in diet coefficients between combined and racial/ethnic-specific models. The overall sample diet was characterized by higher intakes of refined grains and lower intakes of whole grains, solid fats, and nuts and seeds; racial/ethnic-derived diets were similar, with some exceptions. A one-standard deviation increase in the combined pattern was significantly associated with lower BW-for-age (β = -0.08, 95% confidence interval [CI]: -0.16, -0.004), BW (β = -57.5, 95% CI: -94.8, -20.2), and GA at birth (β = -0.13, 95% CI: -0.24, -0.01) and greater odds of preterm birth (OR = 1.41, 95% CI: 1.03, 1.94) and LBW (OR = 1.62, 95% CI: 1.07, 2.46), with pronounced coefficients in racial/ethnic-derived diets. Overall, racial/ethnic-derived FBG diets predicted adverse birth outcomes better than the diet derived from the overall sample in each racial/ethnic group.