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Disparities in adverse birth outcomes may reflect influence of stress.

I am pleased that the recently published article by Tucker et al.1 has brought further attention to the racial disparities of pregnancy-related health outcomes. Dramatic racial disparities exist not only in the risk of death from pregnancy complications but also in the incidence of preterm low-birthweight babies and infant mortality. In the United States, a total of 17.6% of Black babies born to US-born mothers are born preterm (< 37 weeks gestation) as compared with 10.2% of White babies, and 13 % of Black babies born to US-born mothers are born with low birthweights (< 2500 g) as compared with 6.6% of White babies.2 The recent Healthy People 2010 mid-course report indicates that these racial disparities are increasing.3 
 
As Tucker et al. indicate, the reasons for these disparities are unclear. Black women born in Africa and the Caribbean have birth-weight patterns more similar to US-born White women than to US-born Black women, casting serious doubt on genetic factors.4,5 Although Black women in the US military have better birth outcomes than do Black women in the general US population, birth outcomes are still worse than those of their White military peers, even given similar access to prenatal care, similar income, and similar social support.4 The rate of low-birthweight babies among Black, college-educated women is twice that of their White peers, even if both groups of women obtain prenatal care.6 
 
There is increasing evidence linking stress to chronic conditions such as periodontal disease.7 Recent studies also indicate that psychological and physiological stress play a possible role in adverse birth outcomes.8,9 These studies suggest that chronic stress may play a role in adverse pregnancy-related health outcomes, reflecting the role of psychosocial stressors and their influence on the neuroendocrine and immune systems. Individually tailored preconception stress reduction programs may be especially important for Black women and their children to improve life-long health outcomes.