Introduction

Neonatal and infant mortality remains a significant public health issue in the United States. As of 2010, the United States had a 28-day neonatal mortality rate of 4.46 per 1,000 live births, a fetal mortality rate of 6.05 per 1,000 live births, and a 1-y mortality rate of 6.14 per 1,000 live births. There were significant racial/ethnic disparities in these mortality rates. Compared to non-Hispanic white infants, non-Hispanic black infants have a 2.2-fold higher rate of fetal death and infant mortality during the first year of life, and a 2.45-fold increased rate of 28-d neonatal mortality. One key driver of this disparity in infant mortality rates is the increased risk of preterm birth (PTB) in women of minority racial/ethnic status: black women have a 1.6-fold increase in preterm delivery, and a 2.6-fold increase in delivery with a birth weight under 1,500 g.

In order to develop potential interventions to reduce these disparities, it is important to understand the underlying mediators, or causes, for these observed differences. One proposed set of mediating factors is the set of factors known as social determinants of health. Social determinants of health are characteristics that describe how people grow, work, and live, and what their sense of control may be of their environment. These factors may adversely affect the health of an individual, or in this case the fetus or newborn infant. Specific groups of determinants used in this manuscript are based on work from the World Health Organization and the Centers for Disease Control and Prevention and the available literature. These areas include income and other measures of socioeconomic status and wealth; maternal or paternal education; housing status, both individually and of the community someone resides in; the physical environment, including air quality and toxin exposure; and experiences with racism or discrimination, both individually and at the community level as measured through segregation indices. The areas include factors at both the individual level and at the community level.

Table 1 Specific social determinants of health to explain racial/ethnic disparities in pregnancy outcomes, by type of factor

Social determinants of health may affect perinatal outcomes both directly or indirectly. For example, air pollution may induce maternal lung injury leading to hypoxemia in utero, which may result in a small-for-gestational age infant. Crime may directly lead to pediatric injury and possibly higher neonatal or infant mortality. Alternatively, individual or community social factors may lead to either acute stress, inflammation, and higher risk of infection, or chronic stress over the life course of the mother, otherwise known as the weathering phenomenon. These exposures may start as early as in utero and result in fetal programming for other adverse outcomes, such as obesity or hypertension, as the child ages. This toxic stress may result in adverse perinatal outcomes.

Figure 1 Conceptual framework for the relationship between race/ethnicity, social determinants of health, and adverse perinatal outcomes. The four boxes within the social determinants circle represent specific social determinant constructs. Bi-directional arrows demonstrate the complex interaction of different social determinants in determining the ultimate pregnancy outcome.

Much of the current literature on racial/ethnic disparities in perinatal outcome describes the phenomenon without exploring mediating causes for these differences that may be more easily modifiable. Many studies that do examine these intermediate steps typically concentrate on only one mediator, without examining the contribution of other potential mediators listed in Table 1. However, there are recent studies that provide new and innovative insights into this subject. These studies add social determinant data to larger population-based datasets, which enables researchers to examine such factors with adequate statistical power to detect racial/ethnic disparities; explore multiple social constructs in these observed disparities; or account for physical and environmental factors in racial/ethnic differences in outcomes. The objective of this review is to examine this recent research on the association of each set of social determinants on racial/ethnic disparities in PTB, infant mortality, and fetal mortality to highlight potential areas for targeted intervention to reduce these differences. The review will end with potential future research directions in this field.

PTB

Individual Factors

Disparities in PTB persist in the United States and elsewhere, with black women having a 1.6-fold increase in preterm delivery, and a 2.6-fold increase in delivery with a birth weight under 1,500 g. There have been numerous studies examining the potential mediating effect of many individual level social determinants of health presented in Table 1on this differential risk of PTB. These individual level factors include receipt of welfare as a proxy for income; marital status and education level; exposure to racism and racial discrimination; and housing insecurity. In each case, inclusion of these factors individually explained some, but not all, of the observed disparities in PTB rates. For the markers of socioeconomic status, education, and experiences with racial discrimination, these studies found a dose–response effect, where the risk of PTB increases as these measures worsen. Recent work in this field has begun to examine the complex relationship between these measures and PTB, especially how other social determinants and behaviors may modify observed associations between a specific factor and PTB risk. A recent study by Braveman et al. examined the complex relationship between socioeconomic status and racial disparities in PTB rates. This study linked comprehensive social determinant survey data to a large statewide population-based database, demonstrating a significant interaction between race and income, maternal education, and paternal occupation and racial disparities in the risk of PTB. This study found a reduction in the difference in preterm delivery rates between black and white women as community poverty and social depravation increased, with no measured difference when census tract-level poverty was above 25%. In contrast, a study in Australia found that disparities in PTB between Aboriginals and non-Aboriginals were higher in more disadvantaged women compared to less disadvantaged women, where the gap was minimal. It is not clear from the literature why these studies found such different results. For racial discrimination, recent work from Chicago suggests that exposure to discrimination in the year prior to delivery was associated with a higher risk of PTB (OR: 2.5, 95% CI: 1.2–5.2) than reports of exposure to racial discrimination throughout a woman’s life (OR: 1.5, 95% CI: 0.9–2.8). Active coping skills helped to reduce these associations. Thus, while there have been multiple studies examining individual social determinant factors as potential explanatory factors for observed disparities in PTB, there have been limited studies accounting for multiple factors that elucidate the complex relationship that these factors may have on disparities in PTB.

Community Factors

As with individual socioeconomic factors, there have been numerous studies examining the association of community socioeconomic factors and preterm delivery. A systematic review of 106 studies showed a small to moderate association between increased preterm delivery rates and increased poverty, lower income, and higher measures of social depravation. For racial/ethnic differences in preterm delivery, studies have focused in two areas. First, studies stratify the racial/ethnic disparities in preterm delivery rates by levels of poverty and social depravation, such as the work of Braveman discussed in the previous section. Second, studies have performed race-specific regression models to examine the association between these community measures of poverty and preterm delivery risk. This body of work has found conflicting data. Many studies show an increased effect of community poverty on PTB risk for non-Hispanic black women compared to other racial/ethnic groups, whereas other studies have found the opposite effect, specifically when studying the effect of racial/ethnic group density on PTB risk. These studies all suggest that measured community factors have an effect on the risk of preterm delivery, but that the effect may differ between racial/ethnic groups, similar to what has been demonstrated for the effects of individual-level social determinants.

There has been less work investigating the importance of community factors on observed racial/ethnic disparities in PTB rates. A study using data from Durham County and Wake County, NC from 1999–2001 assessed several community factors on a block level to obtain homogeneous measures of the community. These factors spanned the domains of income/poverty, educational attainment, employment, occupation, and housing. Individual socioeconomic factors such as age, education, marital status, and gravity directly explained 40–43% of the racial disparity in preterm delivery rates for this study. However, community factors independently explained 15% of the observed racial disparities in PTB, with smaller contributions to the higher risk of low birth weight (7–8%) and small-for-gestational age (4–5%) in black women included in this study. For PTB, these community factors had the largest effect on racial disparities in moderate PTB rate, explaining 20% of the disparity, compared to extremely preterm deliveries, where neighborhood explained 7–10% of the difference.

The role of community factors across the life course of a woman has been explored in several projects that utilize a unique, generationally-linked birth certificate dataset from Illinois. This work finds several important results. First, lifelong exposure to low-income communities, as assessed by the community income of the grandmother and mother at the times of their respective pregnancies, was associated with a higher rate of low birth weight deliveries regardless of race/ethnicity. However, the population-attributable risk of LBW delivery from lifelong residence in low-income communities differed by race, with a population-attributable risk of 1.6% in non-Hispanic white women, vs. 23.6% in black women. Second, upward mobility, defined as women who resided in high-income communities during their pregnancy but were born in low-income communities, was associated with a lower risk of low birth weight in black women. Finally, increasing maternal age was associated with an increased risk of low birth weight only in black women with longer exposure to low income communities, such that the black women over the age of 30 had an odds ratio of 1.48–1.63 for low birth weight compared to black women under the age of 20. Black women with upward economic mobility, those who resided in high-income areas at both time points measured in this study, and white women did not experience such differential effect.

There are several studies examining the association between the risk of PTB and measures of racial segregation. Table 2 shows the five constructs that assess residential segregation. Most of the existing literature examining the relationship between segregation and PTB uses the isolation construct. In black women, these studies have found a statistically significant association between residing in a more isolated area and PTB risk. White women living in these same highly isolated areas for black women did not experience the same increase in PTB risk as their black counterparts, which suggests that there may be variation in where white and black women reside within these highly isolated communities.

However, there have been few studies of the relationship between other measures of segregation and PTB risk; how different constructs of segregation may interact to influence PTB risk; and how other factors, such as built environment, may mediate these results. Two recent studies have begun to examine these areas. First, a study using US natality data from 2000 examined the influence of “hypersegregation” on PTB risk. In this study, hypersegregation was defined as living in an area that met the criteria for segregation in four of five of these constructs. Twenty-two US metropolitan areas (9%) met these criteria, with 28% of births occurring in these areas. Black women residing in these areas had a 15% higher risk of PTB compared to black women residing in less segregated areas (areas who met the criteria for segregation in three or fewer constructs). This risk remained elevated after controlling for individual measures of socioeconomic status. As with studies using the isolation alone, white women residing in these hypersegregated areas did not have a statistically significant change in their risk of PTB. One other studies found that the isolation and clustering constructs act differently on PTB risk when assessed together: controlling for isolation, higher clustering was associated with a lower risk of PTB for black women. These studies suggest that different segregation constructs may assess different aspects of racial/ethnic segregation, with ensuing different effects on PTB risk.

The second recent study examined the importance of built environment assessed at the census block level on the association between residential segregation and PTB risk. The specific measures included housing damage; property damage; nuisances; home vacancy; crime; and percent home rentals. These built factors mediated 35% of the effect of racial/ethnic isolation on the risk of PTB. This study is important because, while changing racial/ethnic segregation may require a long time horizon, states and local governments may have more tools to combat poor built environment.

There are other limitations in the current state of this literature. First, the role of residential segregation and the built environment have not been examined for disparities in either the fetal or infant mortality rates. In the adult literature, residing in a higher segregated area is associated with a higher risk of mortality in conditions such as cancer and diabetes. Second, most studies in this area use segregation indices from large geographic areas such as the metropolitan statistical area, which may not reflect what an individual woman experiences in her day-to-day activities. This potential misclassification is suggested by differences in the effect of segregation on PTB rates for women of different racial/ethnic status who reside in the same area. Finally, individual level experiences with racism and racial discrimination have not been examined concurrently with measures of community segregation for their combined effects on disparities in PTB.

Physical Environment

There are numerous studies of the association between environmental exposures and pregnancy outcomes. Specific exposures include fine particulate air particles, carbon monoxide, and ozone. Other studies examine the impact of residing near chemical plants, refineries, or other industries. There are also studies that suggest that racial/ethnic minorities are at greater likelihood of residing in communities with higher pollution rates, based on monitoring data from the Environmental Protection Agency. However, there are few studies formally examining whether these environmental exposures explain some of the observed racial/ethnic disparities in perinatal outcomes. One study examined this question using Natality data from 1998–1999 linked to an air pollution index at the county level. Hispanic women (OR: 4.66) and non-Hispanic black women (OR: 2.58) were more likely to reside in a region of increased air pollution. Air pollution was independently associated with higher rates of PTB, but could not explain disparities in PTB risk for either racial/ethnic group. In contrast, a recently published study using particulate air pollutant data in Florida from 2000 to 2007 found an overall increased risk of PTB (OR: 1.12, 95% CI: 1.06–1.18), low-birth-weight (OR: 1.18, 95% CI: 1.11–1.25) and very-low-birth-weight deliveries (OR: 1.27, 95% CI: 1.08–1.49) in the 23.2% of total births that lived in a particulate exposed area. When the effect of exposure to particulate air pollution was examined in non-Hispanic white and black women separately, exposure to air pollution in black women was associated with a 68–300% higher increase odds of these adverse outcomes compared to white women exposed to particulate air pollution.

These studies show the challenges of studying environmental exposures as a mediating factor for racial/ethnic disparities in pregnancy outcomes. In most studies, the exposure data are taken from air pollution monitoring stations, with individual exposure extrapolated from the distance from these stations to a woman’s residence. The accuracy of this assessment depends on the accuracy of residential data (zip code vs. physical address) in the dataset, and the assessment of other potential toxins.

Neonatal Mortality

Black infants die twice as often as white infants, primarily through higher rates of PTB. A similar disparity is seen in the rate of postneonatal mortality. Although health behaviors, such as smoking, substance abuse, and receipt of prenatal care play a role in explaining these disparities, measures of individual sociodemographic status, including income, education and participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), explain a larger portion of the disparities in mortality. However, black infants born to college-educated black parents die at nearly twice the rate of white infants born to college-educated white parents. Other potential factors that may reduce the disparity in neonatal mortality include adequate prenatal care, participation in prenatal WIC and paternal involvement in childrearing.

Studies have also examined community factors to explain disparities in neonatal and infant mortality. Community factors explained almost 50% of the black-white disparity in postneonatal mortality rates in Chicago, with individual factors further explaining an additional 6–7% of the difference. However, in Milwaukee, using income data from residential zip codes, infant mortality rates remained elevated for black children until they resided in the highest income areas, while infant mortality rates for white children began to fall when they resided in middle income areas. This result is similar to newer work on PTB risk.

Other potential factors, such as experiences with discrimination, housing stock, or racial segregation, have not been examined. While there is this literature on potential explanatory factors for disparities in neonatal and postneonatal mortality, there have been no studies that formally evaluate any of the potential individual or community level mediating factors listed in Table 1.

Fetal Mortality

There are also substantial racial and ethnic disparities in the rate of fetal death with several studies demonstrating more than a twofold increase in risk among Black women. There have been, though, few studies of the role of either individual-level or community-level social determinants of health to explain this observed disparity. The best-studied factors are measures of individual socioeconomic status. Similar to PTB, disparities in fetal death are partially, but not completely, explained by these measures, the effect of which may differ between different racial/ethnic groups. For example, maternal age, education, and insurance status as a proxy of household income collectively explained 15% of the black-white disparity in fetal death and 35% of the disparity between Hispanic and non-Hispanic white women in multiple US states. Higher education is associated with a lower risk of stillbirth for both black and white women though the risk reduction is greater for white women. Other potential factors listed in Table 1at all levels have not been formally examined.

Summary and Future Research Needs

In summary, there is an extensive literature that supports the premise that social determinants may mediate or modify observed racial/ethnic differences in perinatal outcomes. The best-studied outcome is PTB risk. Fewer studies explore the mediating factors in the outcomes of fetal death, neonatal death, or postneonatal death, even though similar racial disparities exist for these outcomes. While individual factors are strong predictors of these differences in risk, they do not explain all of the disparity. Recent innovations in study design suggest an important contribution of community and environmental factors to these disparities.

There are a number of potential avenues for further research in this field. These avenues include:

Improved Integration of Patient-Reported Outcomes in Population-Based Datasets

Studies of perinatal outcomes require large datasets to be adequately powered for these rare outcomes. Many of the aforementioned social determinants, though, require patient report of data. The expansion of electronic health records for research purposes is a necessary step toward improving the data available for these studies. However, improved collection and recording of social determinant data within the electronic health record is also needed. Finally, methods to collect this information from patients in a patient-centered, culturally-competent manner are important in order to maintain patient trust and elicit accurate responses.

Evaluating the Importance of Social Determinants Over the Life Course of the Woman

Toxic stress and the weathering phenomenon are two theoretical constructs that underlie the differential risk of preterm delivery and other adverse perinatal outcomes in racial/ethnic minorities. There have been few studies that formally measure and test these hypotheses on a longitudinal level, especially for differences in fetal or infant mortality. These studies would require longitudinally linked data across generations and improved health information on patients as they move across state lines and/or change insurance plans in the United States.

Inclusion of Other Potential Moderating or Mediating Factors Such as Access to Care and Care Quality

Few studies formally evaluate how the effect of these various measures of social determinants are influenced by access to care and the quality of care patients can access. Living in a segregated area has been associated with the higher likelihood of adult black patients receiving surgery at low-quality hospitals and a lower likelihood that black breast cancer patients receive adequate care quality. Early access to high-quality health care at points before, during, and after a pregnancy is another potential area for providers and policy makers to modify some of the adverse consequences of these social determinants of health. Racial/ethnic minorities are at higher risk of receiving care from poor providers, but how this factor relates to observed differences in perinatal outcomes is still not known.

Determining the Impact of Different Mechanisms for Each Adverse Outcome

There are numerous mechanisms by which adverse pregnancy outcomes may occur. For example, PTB may result from spontaneous labor; premature rupture of membranes; or medical indications for maternal reasons among others. Similar heterogeneity also exists for fetal, neonatal, and postneonatal mortality. There are no studies that examine whether specific social determinants may influence the risk of a type of outcome, such as spontaneous PTB, and whether these relationships may better explain the observed racial/ethnic disparities in each adverse pregnancy outcome.

Developing Epigenomic Pathways

There are numerous mechanisms by which these social determinants of health may ultimate result in racial/ethnic disparities in perinatal outcomes. Some researchers have argued that epigenetic changes experienced by minority women may be a pathway that has not been fully explored. Such work requires careful collection of genetic and social determinant data within a large cohort of at-risk women. Improved understanding of these pathways that underlie the large observed differences in adverse perinatal outcomes between women of different races is critical to developing programs to reduce and/or eliminate these disparities in health outcomes. Such innovative studies as those presented above are the first step toward the development of such work.

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Social Determinants of Health and Racial/Ethnic Disparities in Perinatal Outcomes in the United States: A Scoping Review

Neonatal and infant mortality rates in the United States remain disconcertingly high, particularly among minority populations. Non-Hispanic Black infants experience significantly higher rates of fetal death, neonatal mortality, and first-year mortality compared to their non-Hispanic White counterparts. This disparity is largely driven by a heightened risk of preterm birth (PTB) among Black women. Understanding the underlying causes of these disparities is crucial for developing effective interventions. This review focuses on the role of social determinants of health (SDOH) as potential mediators of these disparities, examining recent research on their association with PTB, infant mortality, and fetal mortality.

The Influence of Social Determinants on Preterm Birth

Individual-Level Factors

Persistent disparities in PTB rates are partially attributed to individual-level SDOH. Studies have identified factors such as socioeconomic status (SES) (measured by income, education, occupation), marital status, exposure to racism and discrimination, and housing instability as contributors to this disparity. These studies often reveal a dose-response relationship, where a worsening SDOH profile corresponds to an increased risk of PTB.

Recent research has begun to disentangle the complex interplay between these factors. For instance, studies have shown a significant interaction between race, income, maternal education, paternal occupation, and PTB risk. Furthermore, the timing and intensity of exposure to racial discrimination appear to influence PTB risk, with recent experiences having a more pronounced impact.

Community-Level Factors

Community-level SDOH, particularly socioeconomic indicators, have also been linked to PTB disparities. While studies consistently show an association between community poverty and higher PTB rates, the effect on racial/ethnic disparities is less clear. Some studies suggest that community poverty disproportionately impacts Black women, while others report a more nuanced relationship, highlighting the need for further investigation.

Residential segregation is another crucial community-level factor. Studies primarily utilizing the "isolation" construct of segregation have demonstrated a higher PTB risk among Black women residing in highly segregated areas. However, there is limited research on the impact of other segregation constructs and their potential interaction with factors like the built environment. Emerging evidence suggests that built environment factors, such as housing quality and neighborhood safety, may partially mediate the relationship between segregation and PTB.

The Role of the Physical Environment

Numerous studies highlight the adverse effects of environmental exposures, including air pollution and proximity to industrial sites, on pregnancy outcomes. Research indicates that racial/ethnic minorities are disproportionately exposed to environmental hazards due to residential patterns. However, few studies have directly investigated whether these exposures contribute to racial/ethnic disparities in perinatal outcomes. Available findings are mixed, with some studies suggesting a potential role for air pollution in exacerbating disparities in PTB risk. Further research is needed to clarify the contribution of environmental exposures to perinatal health disparities.

Social Determinants and Neonatal Mortality

The disparity in neonatal mortality rates between Black and White infants is striking. While individual-level factors such as SES, prenatal care utilization, and paternal involvement contribute to explaining this gap, a significant disparity persists even after accounting for these factors. Community-level influences, including socioeconomic conditions, have also been implicated. Notably, studies suggest that Black infants experience higher mortality rates even in higher-income neighborhoods compared to their White counterparts.

Despite the documented disparities in neonatal mortality, research specifically examining the mediating role of SDOH in this context remains limited. Further investigation is warranted to elucidate the impact of factors such as discrimination, housing quality, and segregation on racial/ethnic disparities in neonatal mortality.

Understanding Fetal Mortality Disparities

Racial and ethnic disparities in fetal mortality rates are substantial. However, the role of SDOH in explaining these disparities remains understudied. Similar to PTB, individual-level SES factors appear to partially account for the disparity, but a significant gap persists. The potential contribution of other SDOH, including community-level factors and experiences of discrimination, requires further exploration.

Future Research Directions

Addressing racial/ethnic disparities in perinatal outcomes necessitates a comprehensive understanding of the complex interplay between SDOH and health. Several avenues for future research are crucial:

• Integration of Patient-Reported Outcomes: Incorporating patient-reported data on SDOH into large population-based datasets is essential for capturing the nuances of social and environmental influences. This requires standardized methods for collecting and integrating such data into electronic health records while ensuring cultural sensitivity and patient trust.

• Life-Course Perspective: Investigating the cumulative impact of SDOH throughout a woman's life is critical, particularly in the context of the "weathering hypothesis." Longitudinal studies linking data across generations are needed to understand how early-life exposures and social mobility influence perinatal outcomes.

• Access to and Quality of Care: Examining the moderating role of healthcare access and quality is essential. Research should investigate how disparities in access to timely and high-quality care intersect with SDOH to influence perinatal outcomes.

• Outcome Specificity: Investigating whether specific SDOH differentially impact various subtypes of adverse perinatal outcomes (e.g., spontaneous vs. medically indicated PTB) is crucial for targeted intervention development.

• Exploring Epigenetic Pathways: Understanding the epigenetic mechanisms through which SDOH influence gene expression and contribute to disparities in perinatal outcomes is a promising area of research. Large-scale cohort studies incorporating genetic and social determinant data are needed to unravel these complex pathways.

In conclusion, substantial evidence underscores the significance of SDOH in mediating racial/ethnic disparities in perinatal outcomes. Addressing these disparities requires a multifaceted approach encompassing individual-level interventions, community-level initiatives, and policy changes that mitigate social and environmental inequities. Continued research exploring the complex interplay of SDOH and perinatal health is vital for developing effective strategies to achieve health equity.

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Social Determinants of Health and Racial Disparities in Perinatal Outcomes in the United States

Introduction

Neonatal and infant mortality rates in the United States are a serious public health concern, with significant racial disparities. This article explores the impact of social determinants of health on these disparities, specifically focusing on preterm birth, infant mortality, and fetal mortality.

As of 2010, the United States reported concerning rates for neonatal mortality (death within 28 days of birth), fetal mortality (stillbirth), and infant mortality (death within the first year of life). Disturbingly, these rates are disproportionately higher for Black infants compared to White infants. One of the primary drivers of this disparity is the higher rate of preterm birth (PTB) among Black women. To effectively address these inequities, it's crucial to understand the underlying factors contributing to these disparities.

Social determinants of health, which encompass the conditions in which people live, work, and grow, play a significant role in these disparities. These factors can have both direct and indirect impacts on perinatal outcomes. For instance, air pollution can directly affect fetal health by restricting oxygen supply, while crime can lead to injuries and potentially increase infant mortality. Chronic stress, often stemming from social and economic disadvantages, can also negatively impact maternal and infant health.

This article examines recent research exploring the link between various social determinants and racial disparities in PTB, infant mortality, and fetal mortality rates. The goal is to pinpoint potential areas for targeted interventions to bridge these gaps.

Preterm Birth (PTB)

Individual Factors

Numerous studies have investigated individual-level social determinants, such as income, education, experiences of racism, and housing instability, in relation to PTB disparities. These studies consistently show that these factors contribute to the increased risk of PTB among Black women. Notably, there's a dose-response relationship, meaning the risk of PTB rises as these social disadvantages worsen.

Emerging research delves into the complex interplay of these factors. For example, studies have found that socioeconomic disparities in PTB rates between Black and White women decrease as community poverty levels rise. This suggests that extreme poverty might overshadow the impact of race on PTB risk in certain contexts. Additionally, research on racial discrimination reveals that recent experiences of discrimination have a stronger association with PTB than past experiences.

Community Factors

Similar to individual socioeconomic factors, community-level factors like poverty and social deprivation are linked to higher PTB rates. Research indicates that the impact of community poverty on PTB risk might differ across racial groups. Some studies suggest a greater effect on Black women, while others point to a more nuanced relationship depending on factors like racial segregation.

Studies exploring the influence of racial segregation on PTB primarily focus on the "isolation" aspect, indicating that Black women residing in highly segregated areas experience an elevated risk of PTB. However, this risk doesn't appear to affect White women living in the same areas to the same extent. Recent studies suggest that different dimensions of segregation might have varying effects on PTB risk.

Furthermore, the built environment, encompassing factors like housing conditions and crime rates, can mediate the relationship between segregation and PTB risk. This suggests that improving the built environment could be a more immediate strategy to address disparities while working on long-term solutions for desegregation.

Physical Environment

Environmental exposures, such as air pollution and proximity to industrial sites, have been linked to adverse pregnancy outcomes. Studies using air pollution data have shown a higher risk of PTB, low birth weight, and very low birth weight among mothers residing in areas with higher pollution levels. Importantly, research suggests that Black women might be more vulnerable to the adverse effects of air pollution compared to White women.

Neonatal Mortality

Despite numerous studies highlighting the stark racial disparity in neonatal mortality rates, research specifically examining the role of social determinants in explaining this gap is limited. Existing studies primarily focus on sociodemographic factors like income, education, and participation in nutritional assistance programs. While these factors partially explain the disparities, they don't fully account for the higher mortality rates among Black infants even when controlling for socioeconomic factors.

Community-level factors, such as neighborhood poverty and social environment, also appear to play a role in explaining the disparities in postneonatal mortality rates. However, more research is needed to understand the impact of other social determinants, including experiences of discrimination, housing quality, and racial segregation, on neonatal mortality disparities.

Fetal Mortality

Similar to other perinatal outcomes, racial and ethnic disparities in fetal mortality rates are substantial. Yet, research investigating the role of social determinants in explaining these disparities is limited. Existing studies primarily focus on individual socioeconomic factors, which, while important, do not fully account for the racial disparities in fetal death rates. Further research is crucial to understand the contribution of other social determinants, such as education, access to healthcare, and experiences of discrimination, in explaining these disparities.

Summary and Future Research Needs

In conclusion, substantial evidence suggests that social determinants of health, both at the individual and community levels, contribute to the unacceptable racial and ethnic disparities in perinatal outcomes observed in the United States. To effectively address these inequities and improve health outcomes for all infants, more research is urgently needed.

Future research should prioritize:

• Better integration of patient-reported data on social determinants into large population-based studies.

• Investigating the long-term impact of social determinants on maternal and infant health throughout a woman's life course.

• Examining how access to quality healthcare interacts with social determinants to influence perinatal outcomes.

• Analyzing the relationship between specific social determinants and different causes of adverse pregnancy outcomes.

• Exploring the potential role of epigenetic changes as a pathway linking social determinants to racial disparities in perinatal outcomes.

By deepening our understanding of these complex relationships and prioritizing health equity, we can work toward developing effective interventions and policies to eliminate these disparities and ensure the well-being of all mothers and infants.

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Racial and Ethnic Differences in Pregnancy: Why It Matters and What We Can Do

The Problem

In the US, babies born to Black mothers are more likely to die in the first year of life than babies born to white mothers. This is especially true for babies born too early (premature) or very small. This difference in survival rates is a serious problem.

What Causes These Differences?

Many things play a role, but one important factor is the different life experiences of mothers from different racial and ethnic groups. These are called "social determinants of health." They include things like:

• Money and Resources: How much money a family has and their access to good schools and jobs.

• Education: How much education a mother and father have.

• Where People Live: Safe and affordable housing, clean air, and safe neighborhoods all matter for health.

• Experiences with Racism: Sadly, racism and discrimination are big problems that can affect a person's health, even before a baby is born.

How Social Determinants Affect Babies

Imagine these factors like building blocks for a strong and healthy life. When these blocks are missing or weak, it's harder for moms and babies to thrive. For example:

• Stress: Living in a neighborhood with lots of crime can be very stressful. Stress can make it harder for a woman to have a healthy pregnancy.

• Pollution: Breathing dirty air, especially during pregnancy, can harm a developing baby.

• Healthcare Access: When families lack access to good doctors and healthcare, it's harder to get the care they need for a healthy pregnancy.

What We Know So Far

• Premature Birth: Studies show that Black women are more likely to give birth prematurely. Factors like education, income, and experiences with racism contribute to this, but they don't explain everything.

• Neighborhood Matters: Where a woman lives plays a big role. Living in a neighborhood with poverty, crime, or pollution increases the risk of problems.

• Other Serious Problems: Social determinants also affect other serious issues like babies dying before birth (stillbirth), shortly after birth (neonatal death), or in the first year of life (infant mortality).

What Needs to Happen Next

• Better Information: We need to collect better information about social determinants of health from patients.

• Lifelong Effects: We need to study how a mother's life experiences, starting even before she was born, can affect her children's health.

• Healthcare Access and Quality: Everyone deserves access to good doctors and healthcare. We need to understand how differences in healthcare affect pregnancy outcomes for different racial groups.

• Understanding Specific Causes: We need to figure out exactly how social determinants lead to premature birth and other problems.

• Genetic Research: New research is looking at how our genes and our environment work together to impact health.

The Bottom Line

Racial and ethnic differences in pregnancy outcomes are a serious problem. By understanding the powerful role of social determinants of health, we can start to create solutions that give all babies a fair chance at a healthy start in life.

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Understanding the Challenges Faced by Black Moms and Babies: Why are Some Babies Less Healthy?

It's a sad fact that in the United States, Black babies are more likely to get sick and even pass away during their first year of life compared to White babies. This is a big problem that doctors and scientists are trying hard to understand and fix. One of the main reasons for this difference is that Black mothers are more likely to have their babies too early (premature birth) or have babies that are smaller than they should be. But why is this happening?

One important reason is the different life experiences people have based on their race. These experiences can affect things like where people live, what jobs they have, and the kind of healthcare they receive. Let's explore some of these reasons.

Money and Where People Live

• Having enough money makes a big difference. When families struggle with money, it's harder for moms to eat healthy food, get good medical care, and live in safe neighborhoods. Sadly, Black families are more likely to face these challenges, which can lead to unhealthier babies.

• Neighborhoods matter too. Living in a neighborhood with lots of crime, pollution, or few parks and playgrounds can also be stressful for moms and affect their babies' health. Studies show that Black mothers are more likely to live in these types of neighborhoods.

Feeling Stressed and Treated Unfairly

• Life can be stressful, especially for moms. Facing racism and discrimination because of their race can make Black mothers feel more stressed. This can be harmful to their own health and the health of their babies, even before they are born.

What Can We Do?

It's important to learn about these problems so we can work towards solutions. Here are some things researchers and doctors are working on:

• Asking moms about their lives: It's important for doctors to talk to moms about their home lives, jobs, and experiences to understand how these factors might affect their health and their baby's health.

• Helping moms throughout their lives: Supporting moms with good education, jobs, and safe housing can make a big difference for their health and the health of their families, even before they become pregnant.

• Creating healthier communities: Everyone deserves to live in a safe and healthy neighborhood. Building more parks, reducing pollution, and making sure everyone has access to good schools and jobs can help improve the health of entire communities.

By understanding the challenges and working together, we can create a fairer and healthier world for all babies.

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