We used multilevel covariance structure analysis to study the relationship between birth weight, family context and youth math and reading comprehension growth from approximately ages 5 through 14 within and between families. Using data from the National Longitudinal Survey of Youth Child Sample, we examined the relationship between birth weight and subsequent academic achievement growth disparities, distinguishing between birth weight and other contextual social confounders. We found that smaller birth weight is associated with lower math and reading scores at age 5. Additional findings indicated that the home environment has important developmental consequences from early childhood and into adolescence. Overall, the pattern of findings painted a complex picture of disadvantage, beginning in the womb and extending through a variety of mechanisms into adolescence. (Contains 4 tables, 1 figure, and 5 notes.)