Racial and ethnic disparities in birth outcomes: a life-course perspective.

BACKGROUND: In the United States, Black infants have significantly worse birth outcomes than do White infants. The cause of these persisting racial disparities remains unexplained. Most extant studies focus on differential exposures to protective and risk factors during pregnancy, such as current socioeconomic status, maternal risky behaviors, prenatal care, psychosocial stress, or perinatal infections. These risk factors during pregnancy, however, do not adequately account for the disparities.

METHODS: We conducted a literature review for longitudinal models of health disparities, and presented a synthesis of two leading models, using a life-course perspective. Traditional risk factors during pregnancy are then reexamined within their life-course context. We conclude with a discussion of the limitations and implications of the life-course perspective for future research, practice, and policy development.

RESULTS: Two leading longitudinal models of health disparities were identified and discussed. The early programming model posits that exposures in early life could influence future reproductive potential. The cumulative pathways model conceptualizes decline in reproductive health resulting from cumulative wear and tear to the body's allostatic systems. We propose a synthesis of these two models, using the life-course perspective. Disparities in birth outcomes are the consequences of differential developmental trajectories set forth by early life experiences and cumulative allostatic load over the life course.

CONCLUSIONS: Future research on racial disparities in birth outcomes needs to examine differential exposures to risk and protective factors not only during pregnancy, but over the life course of women. Eliminating disparities requires interventions and policy development that are more longitudinally and contextually integrated than currently prevail.