Objectives. This study assessed the contribution of age and other risk factors to racial disparities in rates of moderately low birthweight (MLBW; 1500–2499 g) and very low birthweight (VLBW; <1500 g).
Methods. Logistic regression models were developed to determine the effects on MLBW and VLBW of maternal age, race, and poverty, adjusting for birth order, smoking, substance abuse, marital status, and educational level. The sample consisted of 158 174 singleton births to US-born African American and White women in New York City between 1987 and 1993.
Results. The effects of maternal age on MLBW varied by race and poverty, with the most extreme effects among poor African American women. The effects of maternal age on VLBW also varied by race, but these effects were not moderated by poverty. Community poverty had a significant effect on MLBW among African American women, but no effect on VLBW. The adverse effect of older maternal age on MLBW and VLBW did not vary with community poverty.
Conclusions. Older maternal age is associated with reduced birthweight among infants born to African American women, and the age effect is exacerbated by individual poverty.