Daniel Kruger, a researcher in the University of Michigan's School of Public Health and Population Studies Center at the Institute for Social Research, contributed this article to LiveScience’s Expert Voices: Op-Ed & Insights.
Public health measures and a scientific approach to medicine have dramatically reduced infant mortality rates in developed countries. Yet, despite decades of clinical, scientific and legislative efforts, infant mortality rates in the United States remain high among developed countries, and wide disparities persist between demographic groups.
Traditional medical risk factors are still important, as are healthy behaviors such as avoiding tobacco and other hazardous substances during pregnancy, but there is growing recognition for the need to examine influences outside of the standard medical model.
Now that infectious disease and other threats have been largely controlled, prematurity and low birth weight are the primary risk factors for infant mortality. Life history theory is providing a powerful framework to help us understand how women's environments and life experiences can shape those birth outcomes. Life history theory describes the trade-offs organisms — including people — make in how they commit finite resources at all stages of life. Two recent studies based on that framework suggest environmental conditions associated with lesser life success discourage successful pregnancies and are predictors of adverse birth outcomes.
The first study, which I published with my colleagues at the Genesee County Health Department, demonstrates that the structural deterioration of a neighborhood is associated with higher rates of premature and low-birth-weight births — an outcome that is beyond the relationship we expect from typical socio-economic predictors. That relationship holds for both African Americans and Whites, but is stronger for African Americans because they are more likely to live in highly deteriorated neighborhoods.
The second study, which I just published this past month with my undergraduate research assistants as co-authors, shows that a scarcity of adult men predicts higher rates of prematurity and low birth weight, even when accounting for a powerful array of socio-demographic predictors. That effect is related to the proportions of households with children that are headed by single mothers, which is the single factor that explains the relationship between socio-economic status and adverse birth outcomes. [News Story: Premature Births Linked to Scarcity of Men]
Previous research shows that the physical deterioration of neighborhoods predicts perceptions of weaker community support and greater concerns about neighborhood safety and crime. Additionally, children who grow up without fathers present are at risk for a wide range of adverse outcomes, and father absence was a strong risk factor for infant and child mortality in pre-modern societies.
The identification of two, new risk factors based on life history theory supports the notion that women have an evolved system for evaluating conditions related to a child's survival throughout human history, although these life history trade-offs may also result in adverse birth outcomes in modern environments.
We can help promote maternal and infant health by embracing the most powerful theories of the life sciences and broadening our perspective on factors important for good health. This would complement the successes achieved through technological advances, which may face diminishing returns.
The views expressed are those of the author and do not necessarily reflect the views of the publisher.
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