Weathering hypothesis

While conducting research in the Department of Public Health Policy and Administration as a graduate student at the University of Michigan in 1992, Geronimus noticed a trend in disparities between the fertility of African American women versus their white counterparts.[11] She noted that while the average white woman experiences her point of highest fertility and lowest risk of pregnancy complications or neonatal mortality between her 20's and 30's, this generalization did not apply to African American women. Instead, among African American women, teen mothers are most likely to have healthy pregnancies and offspring. The data indicated a widening disparity in black-white infant mortality as maternal ages increase. Subsequently, Geronimus proposed the "weathering hypothesis," which she initially conceived as a potential explanation for the patterns of racial variation in infant mortality with increasing maternal age.[10]

Maternal mortality is three to four times higher for Black mothers than white mothers in the United States.[14] Infant mortality is also twice as high for infants born to non-Hispanic Black mothers compared to infants born to non-Hispanic white mothers.[15] Additionally, there are racial disparities for negative birth outcomes like low birth weight, which has been found to influence risk of infant mortality and developmental outcomes after birth, and preterm birth.[14][16] Across all women, older maternal age is associated with higher rates of these negative outcomes during pregnancy, but studies have consistently found that rates rise more rapidly for Black women than white women.[16][17] The weathering hypothesis proposes that the accumulation of racial stress over Black women's lives contributes to this observed pattern of racial disparities in maternal health and birth outcomes that increase with maternal age.[17] Research has consistently identified an association between preterm birth and low birth weight in Black women and maternal stress caused by experiences of racism, systemic bias, socioeconomic disadvantage, segregated neighborhoods, and high rates of violent crime.[15] There is biological evidence of weathering, including the finding that Black women have shorter telomeres, a biological indicator of age, when compared with white women of the same chronological age.[15] Though increased socioeconomic status serves as a protective factor against negative birth outcomes for non-Hispanic white mothers, disproportionate rates of preterm birth and low birth weight for non-Hispanic Black mothers have been found at every education and income level.[15] The weathering hypothesis has also been used to explain this trend because upward socioeconomic mobility is associated with increased exposure to discrimination for women of color.[15]

There is modest evidence supporting the effects of weathering on mothers from other minority groups, including for high birth weight outcomes among American Indian/Alaska Native women.[18] Research has started to explore whether the weathering hypothesis could also explain racial disparities in the outcomes of assisted reproductive technologies, but so far the findings are inconsistent.[19]

Research shows that mental health disparities among marginalized communities exist. Daily discrimination faced by marginalized groups have been found to be associated with increased depressive symptoms and feelings of loneliness.[20] Low-income communities are more likely to have severe mental illnesses, which is frequently heightened by the inaccessibility to quality healthcare.[21] Researchers found that persisting epigenetic changes lead to increased risk of postpartum depression as a result of adverse life events and cumulative life stress among Black, Latinx, and low-income women.[22] In a study assessing African American men, experiences of racism were linked to a poorer mental health state.[23]

Intersectionality is a term coined by Kimberlé Crenshaw to describe the interconnected nature of different systems of oppression, the layered effects of which can be seen in the healthcare system. Research indicates that lower class status and increased depressive symptoms are associated with higher levels of biological weathering among Black individuals in comparison to white individuals.[24] In a study exploring disparities in mental health, researchers found that Black sexual minority women reported higher frequencies of discrimination and decreased levels of social and psychological well-being than their white sexual minority women counterparts.[25] Black sexual minority women had decreased levels of social well-being and increased levels of depressive symptoms in comparison to Black sexual minority men.[25] African American women are also more likely to contract COVID-19 than African American men and white women.[26] The prevalence of medical racism and sexism (lack of quality healthcare, harmful experimentation, etc.) has led to negative relationships with healthcare systems and increased risk of negative sexual and reproductive health outcomes among African American women.[27] Existing research show how systems of oppression work together to oppress marginalized groups within the healthcare system and, as a result, these groups disproportionately experience negative health effects.[26]