Key Points Question Is prenatal dietary quality, assessed with the healthy eating index (HEI) and the empirical dietary inflammatory pattern (EDIP), associated with infant size at birth and infant growth from birth to age 24 months? Findings In this cohort study of 2854 birthing parent–child dyads, higher prenatal HEI scores (indicating healthier diet) were associated with birth weight and growth kinetics within reference ranges. The associations between EDIP and infant growth were less clear.