Maternal age and the size of White, Black, Hispanic, and mixed infants.

Objective: To clarify the interaction between maternal age and race in the prediction of infant size at birth.

Methods: Birth certificate data was used to study the relationship between maternal age, race/ethnicity, and the size of term, singleton infants born to 91,061 healthy, non-smoking, non-substance using, primigravidas.

Results: Maternal race/ethnicity (Black race: OR: 1.