Health disparities are a major public health concern, as are adverse reproductive health outcomes. One of the most persistent health disparities between blacks and whites is that of adverse birth outcomes. This research aimed to evaluate whether racial/ethnic differences in occupational substantive complexity (SC) trajectories were a significant contributor to racial/ethnic disparities in low birth weight (LBW) and preterm delivery (PTD). In addition, this research evaluated racial/ethnic disparities in occupational pathways and the effects on pregnancy outcomes of work that does not fully engage prior education. This was a longitudinal study that analyzed secondary data from the National Longitudinal Study of Youth (NLSY79), combined with occupational characteristics data from the Occupational Information Resource Center (O*NET). Data analysis involved descriptive analysis as well as generalized linear models (GLM) and generalized estimated equations (GEE), which were constructed to examine the associations between outcome and predictor variables, and to estimate the risk of LBW and PTD. Additionally, structural equation modeling (SEM) and general growth mixture models (GGMM) were employed to determine the main effects of longitudinal occupational trajectories relative to educational attainment on LBW and PTD, with particular attention to racial differences. The results of LBW analysis supported the study hypothesis. Minority mothers were over represented in low SC trajectories, and black mothers in particular showed an increased risk of giving birth to a LBW infant. Furthermore, foreign-born Hispanic mothers showed favorable outcomes in comparison to their US-born counterparts. The findings also supported the hypothesis of mediation by SC trajectories of the association between education and LBW. PTD results were inconclusive. Black mothers had an increased risk of PTD as hypothesized, however the mediating effects of SC trajectories were greater for Hispanics. This study is of great relevance to the field of Public Health, as it is adding to the body of knowledge on how disparities in birth outcomes may in part be a consequence of occupational characteristics, which in themselves are expressions, and results of deeper disparities. Additionally with more women working during the course of their pregnancy, this study will be beneficial to women\u27s reproductive health.