African American women's lifetime upward economic mobility and preterm birth: the effect of fetal programming

Neighborhood mobility and racial disparities in preterm birth: A sibling study in California

Recent work finds that upward neighborhood mobility-defined as reductions in neighborhood socioeconomic disadvantage due to moving-may improve birth outcomes. Less work, however, explores whether changes in socioeconomic context differentially impact birth outcomes by maternal race and ethnicity. In the US, mothers of minoritized racial and ethnic identity often experience worse neighborhood conditions and pregnancy outcomes than White mothers. Using a sibling-linked dataset, we examined whether neighborhood mobility corresponds with changes in preterm birth risk among Asian (N = 130,079), Black (N = 50,149), Hispanic (N = 429,938), and White (N = 233,428) mothers who delivered multiple live births in California between 2005 and 2015. We linked residential addresses at each birth to census-derived indices of neighborhood disadvantage and defined levels of neighborhood mobility as moving-induced changes in disadvantage between pregnancies. We mapped neighborhood mobility patterns and fit conditional logistic regression models estimating the odds of preterm birth in the sibling delivered after moving, controlling for the risk of preterm birth in the sibling delivered before moving, by maternal race and ethnicity. Dot density maps highlight racialized patterns of neighborhood mobility and segregation between Black and White mothers. Regression results show that Black and, in some cases, Asian and Hispanic mothers who experienced upward mobility (moves away from neighborhood disadvantage) exhibited reduced odds of preterm birth in the second delivery. Upward mobility did not reduce the odds of preterm birth among White mothers. Findings suggest that policies and programs that enable opportunities for neighborhood mobility may reduce persistent racial and ethnic disparities in adverse birth outcomes.

Lifetime Upward Economic Mobility and US-Born Latina Women's Preterm Birth Rates

OBJECTIVES

To determine whether Latina women's upward economic mobility from early-life residence in impoverished urban neighborhoods is associated with preterm birth (< 37 weeks, PTB) .

METHODS

Multivariate logistic regression analyses were performed on the Illinois transgenerational birth-file with appended US census income information for Hispanic infants (born 1989-1991) and their mothers (born 1956-1976).

RESULTS

In Chicago, modestly impoverished-born Latina women (n = 1,674) who experienced upward economic mobility had a PTB rate of 8.5% versus 13.1% for those (n = 3,760) with a lifelong residence in modestly impoverished neighborhoods; the unadjusted and adjusted (controlling for age, marital status, adequacy of prenatal care, and cigarette smoking) RR equaled 0.65 (0.47, 0.90) and 0.66 (0.47, 0.93), respectively. Extremely impoverished-born Latina women (n = 2,507) who experienced upward economic mobility across their life-course had a PTB rate of 12.7% versus 15.9% for those (n = 3,849) who had a lifelong residence in extremely impoverished neighborhoods, the unadjusted and adjusted RR equaled 0.8 (0.63. 1.01) and 0.95 (0.75, 1.22), respectively.

CONCLUSIONS FOR PRACTICE

Latina women's upward economic mobility from early-life residence in modestly impoverished urban neighborhoods is associated with a decreased risk of PTB. A similar trend is absent among their peers with an early-life residence in extremely impoverished areas.

In Search of the Promised Land: County-Level Disadvantage and Low Birth Weight among Black Mothers of the Great Migration

The Great Migration was a movement of roughly eight million Black Southerners relocating to the North and West from 1910 to 1980. Despite being one of the most significant mass internal migrations during the twentieth century, little is known about the health outcomes resulting from migration and whether migrators' destination choices were potential mechanisms. This study measured the association between destination county disadvantage and odds of low birth weight during the last decade of the Great Migration. We used the US Census from 1970 as well as the birth records of first-time Black mothers who migrated from the South collected through the National Center of Health Statistics from 1973 to 1980 (n = 154,145). We examined three measures of area-based opportunity: Black male high school graduation rate, Black poverty rate, and racialized economic residential segregation. We used multilevel logistic regression, where mothers were nested within US counties, to quantify the relationship between county disadvantage and low birth weight. After adjusting for individual risk and protective factors for infant health, there was no relationship between county opportunity measures and low birth weight among migrators. Although high socioeconomic opportunity is typically associated with protection of low birth weight, we did not see these outcomes in this study. These results may support that persistent racial discrimination encountered in the North inhibited infant health even as migrators experienced higher economic opportunity relative to the South.

Women's Economic Mobility and Small for Gestational Age Rates: The Effect of Paternal Early-Life Socioeconomic Position

OBJECTIVE

To determine whether paternal early-life socioeconomic position (defined by neighborhood income) modifies the association of maternal economic mobility and infant small for gestational age (weight for gestational age < 10th percentile, SGA) rates.

METHODS

Stratified and multilevel binomial regression analyses were executed on the Illinois transgenerational dataset of parents (born 1956-1976) and their infants (born 1989-1991) with appended U.S. census income information. Only Chicago-born women with an early-life residence in impoverished or affluent neighborhoods were studied.

RESULTS

The incidence of impoverished-born women's upward economic mobility among births (n = 3777) with early-life low socioeconomic position (SEP) fathers was less than that of those (n = 576) with early-life high SEP fathers: 56% vs 71%, respectively, p < 0.01. The incidence of affluent-born women's downward economic mobility among births (n = 2370) with early-life low SEP fathers exceeded that of those (n = 3822) with early-life high SEP fathers: 79% vs 66%, respectively, p < 0.01. The adjusted RR of infant SGA for maternal upward (compared to lifelong impoverishment) economic mobility among fathers with early-life low and high SEP equaled 0.68 (0.56, 0.82) and 0.81 (0.47, 1.42), respectively. The adjusted RR of infant SGA for maternal downward (compared to lifelong residence in affluent neighborhoods) economic mobility among fathers with early-life low and high SEP were 1.37 (0.91, 2.05) and 1.17 (0.86, 1.59), respectively.

CONCLUSIONS

Paternal early-life SEP is associated with maternal economic mobility (both upward and downward); however, it does not modify the relationship between maternal economic mobility and infant SGA rates.

Moving to opportunity? Low birth weight outcomes among Southern-born Black mothers during the Great Migration

OBJECTIVE

The Great Migration was a mass movement in the United States during the twentieth century of roughly eight million Black Southerners to the Northeast, Midwest, and West. Despite its significance, little is known about the health outcomes associated with this internal migration. This study assessed the relationship between migration and low birth weight among mothers born in the South between 1950 and 1969.

METHODS

We used approximately 1.4 million birth records of Black infants maintained by the US National Center for Health Statistics. To tease out the roles of the healthy migrant bias and of destination contexts, we compared two migration groups to Southern non-migrators: (1) migrators moving to the North and (2) migrators moving within the South. Non-migrants were matched to migrants using coarsened exact matching. We estimated the relationship between migration status and low birth weight stratified by birth year cohorts using logistic regression models.

RESULTS

There was positive selection in education and marriage among migrants moving out of the South and within the South. Results showed lower odds of low birth weight in both migration groups compared to Southern non-migrants. The odds ratios of low birth weight were similar in both comparisons.

CONCLUSION

We found evidence consistent with a healthy migrant bias in infant health among mothers during the last decades of the Great Migration. Despite better economic opportunity, migrating to the North may not have offered additional protection for infant birth weight outcomes.

The Relation of Neighborhood Racial and Income Polarity to Preterm Birth Rates in Chicago

OBJECTIVES

To investigate the extent to which spatial social polarization is associated with preterm birth among urban African-American and non-Latinx white women, and whether prenatal care modifies this relationship.

METHODS

We performed multilevel logistic regression analyses on a 2013-2017 dataset of Chicago vital records (N = 29,179) with appended Index of Concentration at the Extremes (ICE) values for race and income.

RESULTS

Women who resided in the bottom ICE quintile neighborhoods had a preterm birth rate of 11.5%, compared to 7.3% for those who live in the top ICE quintile areas; adjusted odds ratio (aOR) equaled 1.72 (95% confidence interval [CI] = 1.39, 2.12). This disparity widened for early (< 34 weeks) preterm birth rates, aOR = 2.60 (1.77, 3.81). These associations persisted among women with adequate prenatal care utilization.

CONCLUSIONS FOR PRACTICE

Spatial polarization of race and income in urban African-American and non-Latinx white women's residential environment is strongly associated with preterm birth rates, even among those who receive adequate prenatal care. These findings highlight the benefit of using ICE to contextualize the impact of urban neighborhood-level characteristics on preterm birth rates.

Developmental Origins of Pregnancy-Related Morbidity and Mortality in Black U.S. Women

In the US, Black women are at disproportionate risk for pregnancy-related morbidity and mortality (PRMM). Disparities in PRMM have been tied to elevated rates of obstetric cardiometabolic complications for Black women. Research seeking to elucidate the determinants of Black PRMM to date have focused predominantly on risk factors occurring during pregnancy (e.g., health risk behaviors, quantity and quality of prenatal care, provider behaviors, and attitudes). Meanwhile, other research investigating the developmental origins of health and disease (DOHaD) model indicates that the origins of adult cardiometabolic health can be traced back to stress exposures occurring during the intrauterine and early life periods. Despite the relevancy of this work to Black PRMM, the DOHaD model has never been applied to investigate the determinants of Black PRMM. We argue that the DOHaD model represents a compelling theoretical framework from which to conceptualize factors that drive racial disparities PRMM. Research and intervention working from a developmental origins orientation may help address this urgent public health crisis of Black PRMM.

Telomeres, oxidative stress, and timing for spontaneous term and preterm labor

Telomeres are nucleoprotein complexes located at the distal ends of chromosomes. In adults, progressive telomere shortening occurs throughout the lifetime and is thought to contribute to progressive aging, physiological senescence, multiorgan dysfunction, and ultimately, death. As discussed in this review, multiple lines of evidence provide support for the biological plausibility that a telomere-based clock mechanism also determines the length of gestation, leading to the onset of labor (parturition). After telomere expansion at the beginning of pregnancy, the telomere lengths in the gestational tissues (ie, the placenta and fetal membranes) progressively shorten throughout the remainder of pregnancy. The rate of telomere shortening can be accelerated by conditions that affect the mother and result in oxidative stress. Preterm births in the United States are associated with multiple risk factors that are linked with increased oxidative stress. Antioxidant vitamins (ie, vitamins E and C) mitigate the effects of oxidative stress and delay or prevent telomere shortening. Clinical trials with vitamins E and C and with multivitamins started during the periconception period have been associated with reduced rates of preterm births. In the United States, African-American women have a 2-3-fold higher rate of preterm birth. African-American women have multiple risk factors for premature birth, all of which are distinct and potentially additive with regard to epigenetic telomere shortening. The "weathering effect" is the hypothesis to explain the increased rates of chronic illness, disabilities, and early death observed in African-Americans. With regard to pregnancy, accelerated weathering with the associated telomere shortening in the gestational tissues would not only explain the preterm birth disparity but could also explain why highly educated, affluent African-American women continue to have an increased rate of preterm birth. These studies suggest that the racial disparities in preterm birth are potentially mediated by telomere shortening produced by lifetime or even generational exposure to the effects of systemic racism and socioeconomic marginalization. In conclusion, this review presents multiple lines of evidence supporting a novel hypothesis regarding the biological clock mechanism that determines the length of pregnancy, and it opens the possibility of new approaches to prevent or reduce the rate of spontaneous preterm birth.

Black Babies Matter

Despite dramatic advancements in neonatal intensive care since the 1960s, African-American infants still have more than a two-fold higher first-year mortality rate than non-Latinx White infants. Our essay examines the impact of upstream factors closely linked to the historical and contemporary context of structural racism in the United States on the African-American women's birth outcome disadvantage. In the process, we propose a paradigm to address the racial health inequity in adverse birth outcome by considering the interplay of racism and social class.

Infant Mortality Rates Among US-Born and Foreign-Born Latinx Women: The Effect of Black Race

OBJECTIVE

To determine the extent to which Black race is associated with the infant mortality rate (< 365 day, IMR) of births to US-born and foreign-born Latinx women.

METHODS

Stratified and multivariable binominal log-linear regression analyses were performed on the 2010-2013 National Center for Health Statistics linked birth-death certificate files of singleton infants.

RESULTS

The IMR of births to US-born Black Latinx women (N = 54,542) exceeded that of births to US-born White Latinx women (N = 1,320,084): 5.7/1000 vs 4.2/1000, RR = 1.4 (1.2, 1.5). In contrast, the IMR of births to foreign-born Black Latinx women (N = 35,544) approximated that of births to foreign-born White Latinx women (N = 1,372,172): 3.8/1000 vs 3.6/1000, RR = 1.0 (0.9, 1.2) The adjusted (controlling for maternal age, education, prenatal care, high parity, and region of residence) RR of infant mortality for births to US-born and foreign-born Black (versus non-Latinx White) Latinx women equaled 1.4 (1.2, 1.6) and 1.0 (0.8, 1.2), respectively. The adjusted RR of infant mortality for births to US-born and foreign-born White (versus non-Latinx White) Latinx women equaled 1.0 (0.9, 1.0) and 0.8 (0.7, 0.8), respectively.

CONCLUSIONS

Black race is associated with a 1.4-fold higher IMR among births to US-born Latinx women. A similar phenomenon does not occur among foreign-born Latinx women. These intriguing findings highlight that the social construct of Black race across the life-course of Latinx women are detrimental to infant outcome.

The Impact of Early-Life Exposures on Women's Reproductive Health in Adulthood

Purpose of Review

To review the effects of early-life, preconception, and prior-generation exposures on reproductive health in women.

Recent Findings

Women’s early-life factors can affect reproductive health by contributing to health status or exposure level on entering pregnancy. Alternately, they can have permanent effects, regardless of later-life experience. Nutrition, social class, parental smoking, other adverse childhood experiences, environmental pollutants, infectious agents, and racism and discrimination all affect reproductive health, even if experienced in childhood or in utero. Possible transgenerational effects are now being investigated through three- or more-generation studies. These effects occur with mechanisms that may include direct exposure, behavioral, endocrine, inflammatory, and epigenetic pathways.

Summary

Pregnancy is increasingly understood in a life course perspective, but rigorously testing hypotheses on early-life effects is still difficult. In order to improve the health outcomes of all women, we need to expand our toolkit of methods and theory.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40471-021-00279-0.

Explaining the Black-White Disparity in Preterm Birth: A Consensus Statement From a Multi-Disciplinary Scientific Work Group Convened by the March of Dimes

In 2017-2019, the March of Dimes convened a workgroup with biomedical, clinical, and epidemiologic expertise to review knowledge of the causes of the persistent Black-White disparity in preterm birth (PTB). Multiple databases were searched to identify hypothesized causes examined in peer-reviewed literature, 33 hypothesized causes were reviewed for whether they plausibly affect PTB and either occur more/less frequently and/or have a larger/smaller effect size among Black women vs. White women. While definitive proof is lacking for most potential causes, most are biologically plausible. No single downstream or midstream factor explains the disparity or its social patterning, however, many likely play limited roles, e.g., while genetic factors likely contribute to PTB, they explain at most a small fraction of the disparity. Research links most hypothesized midstream causes, including socioeconomic factors and stress, with the disparity through their influence on the hypothesized downstream factors. Socioeconomic factors alone cannot explain the disparity's social patterning. Chronic stress could affect PTB through neuroendocrine and immune mechanisms leading to inflammation and immune dysfunction, stress could alter a woman's microbiota, immune response to infection, chronic disease risks, and behaviors, and trigger epigenetic changes influencing PTB risk. As an upstream factor, racism in multiple forms has repeatedly been linked with the plausible midstream/downstream factors, including socioeconomic disadvantage, stress, and toxic exposures. Racism is the only factor identified that directly or indirectly could explain the racial disparities in the plausible midstream/downstream causes and the observed social patterning. Historical and contemporary systemic racism can explain the racial disparities in socioeconomic opportunities that differentially expose African Americans to lifelong financial stress and associated health-harming conditions. Segregation places Black women in stressful surroundings and exposes them to environmental hazards. Race-based discriminatory treatment is a pervasive stressor for Black women of all socioeconomic levels, considering both incidents and the constant vigilance needed to prepare oneself for potential incidents. Racism is a highly plausible, major upstream contributor to the Black-White disparity in PTB through multiple pathways and biological mechanisms. While much is unknown, existing knowledge and core values (equity, justice) support addressing racism in efforts to eliminate the racial disparity in PTB.

Prenatal Neighborhood Ethnocultural Context and the Mental Health of Mothers and Children in Low-Income Mexican American Families

Socioeconomically disadvantaged neighborhoods increase the risk for poor mental health among residents, yet protective factors may operate alongside risk. This study evaluated the influence of the prenatal neighborhood ethnocultural context on child behavior problems and maternal depressive symptoms. Prenatal maternal role expectations, prenatal culture-specific stress, and postpartum depression (PPD) symptoms were evaluated as mediators. Participants included 322 low-income, Mexican American mother-child dyads. Women (Mage  = 27.8) reported on proposed mediators, maternal depressive symptoms, and child behavior problems at 4.5 years. Neighborhood Latinx concentration was obtained from census data. Higher Latinx concentration predicted fewer maternal depressive symptoms and child behavior problems, mediated through role expectations and PPD symptoms. Results suggest prenatal neighborhood context to impact later maternal and child mental health.

Understanding Racial Disparities of Preterm Birth Through the Placenta

The racial disparity associated with preterm birth is a public health concern in the United States. The placenta is the principal metabolic, respiratory, and endocrine organ of the fetus and a key route by which environmental exposures are transmitted from mother to offspring. Available at every delivery, it may serve as a marker of differences in prenatal exposures that manifest differently by race. Recently, we described differences in placental pathology between African-American and White preterm births: the prevalence of chronic inflammation was higher among African-American women's placentas compared with those of White women. Similarly, racial differences have been shown in placental malperfusion and placental weight. Social determinants such as poverty and stress from discrimination have been implicated in racial disparities in preterm birth. To date, however, the underlying biological mechanisms, whether through inflammatory, oxidative stress, or other pathways involving epigenetic programming, remain largely unknown. The placenta, complemented by maternal and umbilical cord blood biomarkers, may provide important information on the perinatal environment that explains the origins of racial disparities in preterm birth rates and subsequent health outcomes. This article reviews existing literature and current research gaps. Opportunities are discussed for future placental research that may reveal novel mechanisms leading to the development of new approaches in the prevention and management of preterm birth and its outcomes.

Risk and Protective Factors for Preterm Birth Among Black Women in Oakland, California

This project examines risk and protective factors for preterm birth (PTB) among Black women in Oakland, California. Women with singleton births in 2011-2017 (n = 6199) were included. Risk and protective factors for PTB and independent risk groups were identified using logistic regression and recursive partitioning. Having less than 3 prenatal care visits was associated with highest PTB risk. Hypertension (preexisting, gestational), previous PTB, and unknown Women, Infant, Children (WIC) program participation were associated with a two-fold increased risk for PTB. Maternal birth outside of the USA and participation in WIC were protective. Broad differences in rates, risks, and protective factors for PTB were observed.

Non-Hispanic White Women's Exposure to Decreased Neighborhood Income and Small for Gestational Age Births: A Population-Based Study

BACKGROUND

The relationship between non-Hispanic White (NHW) women's decreased neighborhood income between early-life and adulthood, individual risk-status at delivery, and small for gestational age (weight for gestation < 10th percentile, SGA) rates is unknown.

OBJECTIVE

To determine the extent to which NHW women's exposure to decreased neighborhood income is a risk factor for SGA births, and whether their own birth weight modifies this relationship.

METHODS

Stratified and multilevel logistic regression analyses were executed on the Illinois transgenerational dataset of mothers (born 1956-1976) and their infants (born 1989-1991) with appended U.S. census income information. Only NHW women with an early-life residence in top income quartile Chicago neighborhoods were studied.

RESULTS

NHW women (n = 4889) unexposed to decreased neighborhood income between early-life and adulthood had an SGA rate of 7.1%. In contrast, NHW women exposed to slightly (n = 5112), modestly (n = 2158), or severely (n = 339) decreased neighborhood income by the time of delivery had SGA rates of 8.2%, 10.8%, and 10.8%, respectively; RR (95% CI) equaled 1.2 (1.0-1.3), 1.5 (1.3-1.8) and 1.5 (1.1-2.1), respectively. The relationship between maternal exposure to modestly decreased neighborhood income and SGA rates was present only among former non-low birth weight (> 2500 g, non-LBW) mothers. In multilevel logistic regression models, the adjusted (controlling for age, parity, prenatal care usage, and cigarette smoking) OR of SGA birth for former low birth weight (< 2500 g, LBW) and non-LBW NHW women exposed to modestly (compared to no) decreased neighborhood income equaled 0.7 (0.4, 1.4) and 1.3 (1.1-1.6), respectively.

CONCLUSIONS FOR PRACTICE

NHW women's exposure to modestly decreased neighborhood income is associated with an increased risk of SGA birth; this phenomenon is absent among former low birth weight women.

Neighborhood Privilege, Preterm Delivery, and Related Racial/Ethnic Disparities: An Intergenerational Application of the Index of Concentration at the Extremes

We assessed whether early childhood and adulthood experiences of neighborhood privilege, measured by the Index of Concentration at the Extremes (ICE), were associated with preterm delivery and related racial/ethnic disparities using intergenerationally linked birth records of 379,794 California-born primiparous mothers (born 1982-1997) and their infants (born 1997-2011). ICE measures during early childhood and adulthood approximated racial/ethnic and economic dimensions of neighborhood privilege and disadvantage separately (ICE-income, ICE-race/ethnicity) and in combination (ICE-income + race/ethnicity). Results of our generalized estimating equation models with robust standard errors showed associations for ICE-income and ICE-income + race/ethnicity. For example, ICE-income + race/ethnicity was associated with preterm delivery in both early childhood (relative risk (RR) = 1.12, 95% confidence interval (CI): 1.08, 1.17) and adulthood (RR = 1.07, 95% CI: 1.03, 1.11). Non-Hispanic black and Hispanic women had higher risk of preterm delivery than white women (RR = 1.32, 95% CI: 1.28, 1.37; and RR = 1.11, 95% CI: 1.08, 1.14, respectively, adjusting for individual-level confounders). Adjustment for ICE-income + race/ethnicity at both time periods yielded the greatest declines in disparities (for non-Hispanic black women, RR = 1.23, 95% CI: 1.18, 1.28; for Hispanic women, RR = 1.05, 95% CI: 1.02, 1.09). Findings support independent effects of early childhood and adulthood neighborhood privilege on preterm delivery and related disparities.

How Depressive Symptoms among African American Women Relate to Measures of Social Disorder in Her Childhood and Pregnancy Neighborhood

Pregnant African American women who report higher levels of social disorder (e.g., vacant housing, drug dealing) in their neighborhoods also report higher levels of depressive symptoms. The effects of social disorder in the neighborhood during childhood on depressive symptoms during pregnancy are not known. Also unknown is the interaction between social disorders in the neighborhood during childhood and during pregnancy regarding depressive symptoms during pregnancy. The purpose of this study was to examine whether higher levels of social disorder in the neighborhood during pregnancy buffered the association of social disorder in the neighborhood during childhood (at age 10 as reference) with depressive symptoms during pregnancy among African American women. We conducted a secondary data analysis of 1383 African American women from the Life-course Influences on Fetal Environments (LIFE) Study (Detroit, Michigan, 2009-2011). Women were interviewed in the hospital 24-72 h after the births. The Center for Epidemiological Studies-Depression (CES-D) scale measured depressive symptoms. Scales measuring social disorder in the neighborhood both during childhood and during pregnancy were also included in the interviews. Women with CES-D scores ≥ 16 were younger, were more likely to be single, and had lower levels of education and household income compared with women with CES-D < 16. There was a significant association between women who report social disorder in their neighborhoods during childhood and depressive symptoms during pregnancy. This effect was moderated by measures of social disorder in the neighborhood during pregnancy (p = .037). Women who reported both low levels of social disorder in their neighborhoods during childhood and during pregnancy had the lowest CES-D scores after controlling for maternal age, marital status, years of education, and family income. The model had a good fit to the data (χ²₍₆₎ = 6.36, p = .38). Health care providers should inquire about neighborhood conditions during childhood and during pregnancy and provide referrals for appropriate professional and community support for women who report social disorder in their neighborhoods and depressive symptoms.

Socioeconomic Status, Preeclampsia Risk and Gestational Length in Black and White Women

BACKGROUND

Higher socioeconomic status (SES) has less impact on cardio-metabolic disease and preterm birth risk among Black women compared to White women, an effect called "diminishing returns." No studies have tested whether this also occurs for pregnancy cardio-metabolic disease, specifically preeclampsia, or whether preeclampsia risk could account for race-by-SES disparities in birth timing.

METHODS

A sample of 718,604 Black and White women was drawn from a population-based California cohort of singleton births. Education, public health insurance status, gestational length, and preeclampsia diagnosis were extracted from a State-maintained birth cohort database. Age, prenatal care, diabetes diagnosis, smoking during pregnancy, and pre-pregnancy body mass index were covariates.

RESULTS

In logistic regression models predicting preeclampsia risk, the race-by-SES interaction (for both education and insurance status) was significant. White women were at lower risk for preeclampsia, and higher SES further reduced risk. Black women were at higher risk for preeclampsia, and SES did not attenuate risk. In pathway analyses predicting gestational length, an indirect effect of the race-by-SES interaction was observed. Among White women, higher SES predicted lower preeclampsia risk, which in turn predicted longer gestation. The same was not observed for Black women.

CONCLUSIONS

Compared to White women, Black women had increased preeclampsia risk. Higher SES attenuated risk for preeclampsia among White women, but not for Black women. Similarly, higher SES indirectly predicted longer gestational length via reduced preeclampsia risk among White women, but not for Black women. These findings are consistent with diminishing returns of higher SES for Black women with respect to preeclampsia.

"We have this awesome organization where it was built by women for women like us": Supporting African American women through their pregnancies and beyond

Infant mortality is a problem that disproportionately affects infants of African American women, particularly residents in underserved neighborhoods. Chronic stress due to racism has been identified as an important factor in infant mortality. This study examined a novel community-based perinatal support professional (PSP) program, Birthing Beautiful Communities (BBC), in Cleveland, Ohio. BBC provides services for pregnant African American women in underserved neighborhoods with the goal of decreasing infant mortality and low birthweight rates by addressing chronic stress. Focus groups and one individual interview were conducted with the program's 14 PSPs, and 25 clients were interviewed individually. Interviews were analyzed inductively using qualitative thematic analysis to identify pervasive themes. Coders identified major themes of stress, resilience, community, cultural matching, advocacy, self-care, transformation, and self-actualization. BBC PSPs and clients alike reported the program is transforming the lives of clients by helping them address stressors. Findings suggest the community-based PSP model is an important but underused intervention in addressing infant mortality.

Preterm birth in evolutionary context: a predictive adaptive response?

Preterm birth is a significant public health problem worldwide, leading to substantial mortality in the newborn period, and a considerable burden of complications longer term, for affected infants and their carers. The fact that it is so common, and rates vary between different populations, raising the question of whether in some circumstances it might be an adaptive trait. In this review, we outline some of the evolutionary explanations put forward for preterm birth. We specifically address the hypothesis of the predictive adaptive response, setting it in the context of the Developmental Origins of Health and Disease, and explore the predictions that this hypothesis makes for the potential causes and consequences of preterm birth. We describe how preterm birth can be triggered by a range of adverse environmental factors, including nutrition, stress and relative socioeconomic status. Examining the literature for any associated longer-term phenotypic changes, we find no strong evidence for a marked temporal shift in the reproductive life-history trajectory, but more persuasive evidence for a re-programming of the cardiovascular and endocrine system, and a range of effects on neurodevelopment. Distinguishing between preterm birth as a predictive, rather than immediate adaptive response will depend on the demonstration of a positive effect of these alterations in developmental trajectories on reproductive fitness. This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.

The relationship of cervical microbiota diversity with race and disparities in preterm birth

OBJECTIVE

Pregnant non-Hispanic blacks (NHB) have increased vaginal microbiome diversity compared to non-Hispanic whites (NHW) which may contribute to increased preterm birth. Cervical microbiome diversity is poorly characterized in pregnancy, therefore our objective was to correlate cervical microbiota diversity with cervico-vaginal inflammation by race and delivery timing.

STUDY DESIGN

Pregnant women were recruited in the first and second trimesters. A sterile cervical swab and saline lavage were collected at a single time point. Using 16S rRNA sequencing, Chao1 and Shannon Diversity (SDI) indicies were measured and compared by race and delivery timing (preterm vs. term delivery). Cervico-vaginal inflammatory markers were also compared by race and delivery timing. Spearman correlation coefficients between cervical microbiome diversity and cervico-vaginal inflammatory markers were calculated.

RESULTS

Of the 51 subjects, 39 (76%) were NHB and 12 (24%) were NHW. Cervical microbiota SDI was significantly higher in NHB compared to NHW (0.5 vs. 0.1; p = 0.03). However, there were no difference in Chao1 diversity or cervico-vaginal inflammatory markers by race or delivery timing.

CONCLUSION

Our findings suggest the cervical microbiota diversity during pregnancy differs by race. Larger cohort studies will further determine if altered cervical diversity is part of the pathogenesis of PTB and explains race disparities.

African-American women's Upward Economic Mobility and Small for Gestational Age Births: A Population-Based Study

Background The relationship between African-American women's upward economic mobility and small for gestational age (weight for gestational < 10th percentile, SGA) rates is incompletely understood. Objective To ascertain the extent to which African-American women's upward economic mobility from early-life impoverishment is coupled with reduced SGA rates. Methods Stratified and multilevel logistic regression analyses were completed on the Illinois transgenerational dataset of African-American infants (1989-1991) and their Chicago-born mothers (1956-1976) with linked U.S. census income information. Results Impoverished-born (defined as lowest quartile of neighborhood income distribution) African-American women (n = 4891) who remained impoverished by the time of delivery had a SGA rate of 19.7%. Individuals who achieved low (n = 5827), modest (n = 2254), or high (n = 732) upward economic mobility by adulthood had lower SGA rates of 17.2, 14.8, and 13.7%, respectively; RR = 0.9 (0.8-0.9), 0.8 (0.7-0.8), and 0.7 (0.6-0.8), respectively. In adjusted (controlling for traditional individual-level risk factors) multilevel regression models, there was a decreasing linear trend in SGA rates with increasing levels of upward economic mobility; the adjusted RR of SGA birth for impoverished-born African-American women who experienced low, modest, of high (compared to no) upward mobility equaled 0.95 (0.91, 0.99), 0.90 (0.83, 0.98), and 0.86 (0.75, 0.98), respectively, p < 0.05. Conclusions African-American women's upward economic mobility from early-life residence in poor urban communities is associated with lower SGA rates independent of adulthood risk status.

The South Carolina Multigenerational Linked Birth Dataset: Developing Social Mobility Measures Across Generations to Understand Racial/Ethnic Disparities in Adverse Birth Outcomes in the US South

Objectives To describe the creation of a multigenerational linked dataset with social mobility measures for South Carolina (SC), as an example for states in the South and other areas of the country. Methods Using unique identifiers, we linked birth certificates along the maternal line using SC birth certificate data from 1989 to 2014, and compared the subset of records for which linking was possible with two comparison groups on sociodemographic and birth outcome measures. We created four multi-generational social mobility measures using maternal education, paternal education, presence of paternal information, and a summary score incorporating the prior three measures plus payment source for births after 2004. We compared social mobility measures by race/ethnicity. Results Of the 1,366,288 singleton birth certificates in SC from 1989 to 2014, we linked 103,194, resulting in 61,229 unique three-generation units. Mothers and fathers were younger and had lower education, and low birth weight was more common, in the multigenerational linked dataset than in the two comparison groups. Based on the social mobility summary score, only 6.3% of White families were always disadvantaged, compared to 30.4% of Black families and 13.2% of Hispanic families. Moreover, 32.8% of White families were upwardly mobile and 39.1% of Black families were upwardly mobile, but only 29.9% of Hispanic families were upwardly mobile. Conclusions for Practice When states are able to link individuals, birth certificate data may be an excellent source for examining population-level relationships between social mobility and adverse birth outcomes. Due to its location in the Deep South, the multigenerational SC dataset may be particularly useful for understanding racial/ethnic difference in social mobility and birth outcomes.

Maternal Pre-Pregnancy Cardiovascular Risk Factors and Offspring and Grandoffspring Health: Bogalusa Daughters

Both maternal pre-pregnancy body mass index (BMI) and gestational weight gain have been associated with cardiovascular health in the offspring beyond two generations. A total of 274 daughters (aged 12⁻54) of 208 mothers who participated in the Bogalusa Heart Study were interviewed about their reproductive history. Mothers' data was taken from the original study, and cardiovascular measures at the visit prior to pregnancy were correlated with daughter's measures. Maternal pre-pregnancy BMI, skinfold, and waist circumference were examined as a predictor of daughters' blood pressure, lipids, and glucose, as well as a predictor of birthweight and gestational age of grandchildren. Maternal pre-pregnancy BMI was associated with higher blood pressure and lower low-density lipoprotein (LDL) and cholesterol in the daughters. Most maternal cardiometabolic risk factors were not associated with grandchildren's birth outcomes, even though higher cholesterol and LDL was associated with lower gestational age, and higher BMI and skinfold thickness with an increased risk of preterm birth. In this pilot study, some associations were found between maternal adiposity and cardiovascular risk, daughters' cardiovascular risk, and grandchild birth outcomes. Lack of conclusive associations could be due to a true lack of effect, effects being primarily mediated through daughter's BMI, or the low power of the study.

Life-course neighbourhood opportunity and racial-ethnic disparities in risk of preterm birth

BACKGROUND

Neighbourhood opportunity, measured by poverty, income and deprivation, has been associated with preterm birth, however little is known about the contribution of early-life and life-course neighbourhood opportunity to preterm birth risk and racial-ethnic disparities. We examined maternal early-life and adult neighbourhood opportunity in relation to risk of preterm birth and racial-ethnic disparities in a population-based cohort of women under age 30.

METHODS

We linked census tract poverty data to 2 generations of California births from 1982-2011 for 403 315 white, black, or Latina mothers-infant pairs. We estimated the risk of preterm birth, and risk difference (RD) comparing low opportunity (≥20% poverty) in early life or adulthood to high opportunity using targeted maximum likelihood estimation.

RESULTS

At each time point, low opportunity was related to increased preterm birth risk compared to higher opportunity neighbourhoods for white, black and Latina mothers (RDs 0.3-0.7%). Compared to high opportunity at both time points, risk differences were generally highest for sustained low opportunity (RD 1.5, 1.3, and 0.7% for white, black and Latina mothers, respectively); risk was elevated with downward mobility (RD 0.7, 1.3, and 0.4% for white, black and Latina mothers, respectively), and with upward mobility only among black mothers (RD 1.2%). The black-white preterm birth disparity was reduced by 22% under high life-course opportunity.

CONCLUSIONS

Early-life and sustained exposure to residential poverty is related to increased PTB risk, particularly among black women, and may partially explain persistent black-white disparities.

Pockets of progress amidst persistent racial disparities in low birthweight rates

Racial disparities persist in adverse perinatal outcomes such as preterm birth, low birthweight (LBW), and infant mortality across the U.S. Although pervasive, these disparities are not universal. Some communities have experienced significant improvements in black (or African American) birth outcomes, both in absolute rates and in rate ratios relative to whites. This study assessed county-level progress on trends in black and white LBW rates as an indicator of progress toward more equal birth outcomes for black infants. County-level LBW data were obtained from the 2003 to 2013 U.S. Natality files. Black LBW rates, black-white rate ratios and percent differences over time were calculated. Trend lines were first assessed for significant differences in slope (i.e., converging, diverging, or parallel trend lines). For counties with parallel trend lines, intercepts were tested for statistically significant differences (sustained equality vs. persistent disparities). To assess progress, black LBW rates were compared to white LBW rates, and the trend lines were tested for significant decline. Each county's progress toward black-white equality was ultimately categorized into five possible trend patterns (n = 408): (1) converging LBW rates with reductions in the black LBW rate (decreasing disparities, n = 4, 1%); (2) converging LBW rates due to worsening white LBW rates (n = 5, 1%); (3) diverging LBW rates (increasing disparities, n = 9, 2%); (4) parallel LBW rates (persistent disparities, n = 373, 91%); and (5) overlapping trend lines (sustained equality, n = 18, 4%). Only four counties demonstrated improvement toward equality with decreasing black LBW rates. There is significant county-level variation in progress toward racial equality in adverse birth outcomes such as low birthweight. Still, some communities are demonstrating that more equitable outcomes are possible. Further research is needed in these positive exemplar communities to identify what works in accelerating progress toward more equal birth outcomes.

Maternal Black Race and Persistent Wheezing Illness in Former Extremely Low Gestational Age Newborns: Secondary Analysis of a Randomized Trial

OBJECTIVE

To evaluate the relationship between maternal self-reported race/ethnicity and persistent wheezing illness in former high-risk, extremely low gestational age newborns, and to quantify the contribution of socioeconomic, environmental, and biological factors on this relationship.

STUDY DESIGN

We assessed persistent wheezing illness determined at 18-24 months corrected (for prematurity) age in survivors of a randomized trial. Parents/caregivers were surveyed for wheeze and inhaled asthma medication use quarterly to 12 months, and at 18 and 24 months. We used multivariable analysis to evaluate the relationship of maternal race to persistent wheezing illness, and identified mediators for this relationship via formal mediation analysis.

RESULTS

Of 420 infants (25.2 ± 1.2 weeks of gestation and 714 ± 166 g at birth, 57% male, 34% maternal black race), 189 (45%) had persistent wheezing illness. After adjustment for gestational age, birth weight, and sex, infants of black mothers had increased odds of persistent wheeze compared with infants of nonblack mothers (OR = 2.9, 95% CI 1.9, 4.5). Only bronchopulmonary dysplasia, breast milk diet, and public insurance status were identified as mediators. In this model, the direct effect of race accounted for 69% of the relationship between maternal race and persistent wheeze, whereas breast milk diet, public insurance status, and bronchopulmonary dysplasia accounted for 8%, 12%, and 10%, respectively.

CONCLUSIONS

Among former high-risk extremely low gestational age newborns, infants of black mothers have increased odds of developing persistent wheeze. A substantial proportion of this effect is directly accounted for by race, which may reflect unmeasured environmental influences, and acquired and innate biological differences.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01022580.

Associations between cumulative neighborhood deprivation, long-term mobility trajectories, and gestational weight gain

Existing research on neighborhood environment and gestational weight gain (GWG) focuses on point-in-time measures of neighborhood context. This precludes understanding how long-term exposure to adverse neighborhood environments influences GWG. We estimated associations between average exposure to and trajectories of long-term neighborhood socioeconomic deprivation and risk of inadequate or excessive GWG. Using data from 5690 full-term, singleton pregnancies in the 1979 National Longitudinal Survey of Youth, we estimated associations between cumulative deprivation and GWG, overall and by race/ethnicity, controlling for individual and residential covariates. A one standard deviation unit (8-point) increase in neighborhood deprivation increased risk of inadequate GWG (Relative Risk (RR): 1.08; 95% Confidence Interval (CI): 1.00-1.16) for all women and excessive GWG (RR: 1.11; 95% CI 1.02-1.21) for white women. Persistent low deprivation (RR: 0.78; 95% CI: 0.64-0.94) and upward mobility (RR: 0.76; 95% CI: 0.61-0.96), compared to persistent high deprivation, reduced risk of inadequate GWG. Persistent low deprivation also reduced risk of excessive GWG (RR: 0.84; 95% CI: 0.71-0.98). Long-term neighborhood deprivation contributes to patterns of GWG over women's life course.

Preterm birth and the timing of puberty: a systematic review

BACKGROUND

An estimated 11% of births occur preterm, and survival is improving. Early studies suggested an association between preterm birth and earlier puberty. Given the adverse outcomes associated with early puberty this could have significant public health implications. The objective of this review was to assess the timing of puberty after preterm birth.

METHODS

Pubmed, Embase, Popline, Global Health and Global Health Library were searched using terms relating to "premature birth", "menarche", "puberty" and "follow up studies". Inclusion criteria were a population consisting of pubertal or post-pubertal adolescents and adults; studies which defined preterm delivery in participants and compared outcomes to those after term delivery; and a quantitative assessment of pubertal onset. Assessment of risk of bias was conducted using principles from the Critical Appraisal Study Process.

RESULTS

Our search identified 1051 studies, of which 16 met the inclusion criteria. In females, 8 studies found no association between preterm birth and the timing of menarche. Five studies found earlier onset in preterm infants, 1 found later onset, and 1 showed both earlier and later menarche, depending on birth weight. The range of effect of studies showing earlier menarche was - 0.94 to -0.07 years in the preterm group, with a median of - 0.3 years. In males, 2 studies showed earlier onset of puberty in the preterm group, 5 showed no difference, and 1 showed later onset. Most studies did not present outcomes in the form of a mean with standard deviation, precluding a meta-analysis. There was insufficient data to address potential confounding factors.

CONCLUSIONS

The published evidence does not suggest that being born preterm leads to a significant acceleration in the onset of puberty. This should prove reassuring for public health purposes, and for clinicians counseling parents of infants born preterm.

Racial disparity in infant mortality

In the United States, African-American infants have significantly higher mortality than white infants. Previous work has identified associations between individual socioeconomic factors and select community-level factors. In this review, the authors look beyond traditional risk factors for infant mortality and examine the social context of race in this country, in an effort to understand African-American women's long-standing birth outcome disadvantage. In the process, recent insights are highlighted concerning neighborhood-level factors such as crime, segregation, built environment, and institutional racism, other likely causes for the poor outcomes of African-American infants in this country compared with infants in most other industrialized nations.

Transgenerational Transmission of Preterm Birth Risk: The Role of Race and Generational Socio-Economic Neighborhood Context

Objectives We investigated associations of mothers' preterm birth (PTB) status with her infants' PTB risk. We also examined whether this relationship differs by mothers' race and generational socio-economic neighborhood context. Methods Participants were 6592 non-Hispanic (NH) white and NH black mother-infant pairs born in 2009-2011 and 1979-1998, respectively, in Allegheny County, Pennsylvania. Birth records were used to determine gestational age at birth, PTB status (<37 completed weeks of gestation), and PTB subgroups-late and early PTB (34-36 weeks and <34 completed weeks of gestation, respectively). Census data on tract racial composition and household income were used to characterize residential race and economic environment. Logistic regression models were used to calculate Odds Ratios (ORs), Relative Risk Ratios (RRR), and 95% confidence intervals (CIs). Stratified analyses were conducted to assess effect modification. Results Overall, 8.21, 6.63 and 1.58% infants had PTB, LPTB, and EPTB, respectively. Maternal PTB status was associated with a 46% increase in infant PTB (95% CI: 1.08-1.98), EPTB (95% CI: 0.80-2.69), and LPTB (95% CI: 1.04-2.04) risk. Maternal PTB-infant PTB associations, particularly maternal PTB-infant LPTB associations, were stronger among NH blacks, mothers in neighborhoods with a high percentage of NH black residents in both generations, or mothers who moved to neighborhoods with a higher percentage of NH black residents. Conclusions for Practice Race and generational socio-economic neighborhood context modify transgenerational transmission of PTB risk. These findings are important for identification of at-risk populations and to inform future mechanistic studies.

Life-course Social Mobility and Reduced Risk of Adverse Birth Outcomes

INTRODUCTION

Higher adult socioeconomic position (SEP) is associated with better birth outcomes. However, few studies incorporate life-course or intergenerational SEP, which may inform etiology and targeted prevention efforts. This study tested whether life-course social mobility from childhood was associated with lower risk of adverse birth outcomes.

METHODS

Data were from the Life-course Influences of Fetal Environments (LIFE) retrospective cohort study among black women, 2009-2011, in metropolitan Detroit, MI. This study (analyzed in 2014-2016) examined whether social mobility was associated with two primary birth outcomes: small for gestational age (SGA) and preterm birth (PTB). Childhood and adulthood SEP were measured by survey in adulthood, for two constructs, measured ordinally: educational attainment and perceived financial sufficiency (subjective income/wealth). Social mobility was calculated as the difference of adulthood minus childhood SEP.

RESULTS

In covariate-adjusted Poisson regression models, 1-SD improved educational social mobility from childhood to adulthood was protective for SGA (adjusted risk ratio=0.76; 95% CI=0.64, 0.91); this association remained after adjusting for financial mobility. Upward financial social mobility from early childhood was marginally protective for SGA (adjusted risk ratio=0.85; 95% CI=0.72, 1.02), but became nonsignificant after controlling educational mobility. There were no overall associations of social mobility with PTB or low birth weight, although sensitivity analyses identified that improved financial mobility was associated with 16% marginally lower risk of spontaneous PTB and 28% marginally lower risk of low birth weight among upwardly mobile/stable women only.

CONCLUSIONS

Improved life-course social mobility is associated with reduced risk for SGA and spontaneous PTB among black women.

Born early and born poor: An eco-bio-developmental model for poverty and preterm birth

Poverty is associated with adverse long-term cognitive outcomes in children. Poverty is also linked with preterm delivery which, in turn, is associated with adverse cognitive outcomes. However, the extent of the effect of poverty on preterm delivery, as well as proposed mechanisms by which they occur, have not been well described. Further, the impact of poverty on preterm school readiness has not been reviewed. As the childhood poverty level continues to increase in the U.S., we examine the evidence around physiological, neurological, cognitive and learning outcomes associated with prematurity in the context of poverty. We use the evidence gathered to suggest an Eco-Bio-Developmental model, emphasizing poverty as a toxic stress which predisposes preterm birth and which, via epigenetic forces, can continue into the next generation. Continued postnatal social disadvantage for these developmentally high-risk preterm infants is strongly linked with poor neurodevelopmental outcomes, decreased school readiness, and decreased educational attainment which can perpetuate the poverty cycle. We suggest social remedies aimed at decreasing the impact of poverty on mothers, fathers, and children which may be effective in reducing the burden of preterm birth.

Downward economic mobility and preterm birth: an exploratory study of Chicago-born upper class White mothers

A paucity of published data exists on the factors underlying the relatively poor birth outcome of non-Hispanic White women in the United States. To determine whether downward economic mobility is a risk factor for preterm birth (<37 weeks, PTB) among upper class-born White women. Stratified and multilevel logistic regression analyses were performed on an Illinois transgenerational dataset of non-Hispanic White infants (1989-1991) and their women (1956-1976) with appended US census income information. The study sample was restricted to singleton births of Chicago-born upper-class (defined by early-life residence in affluent neighborhoods) non-Hispanic White women. Upper class-born White women (n = 4,891) who did not experience downward economic mobility by the time of delivery had a PTB rate of 5.4 %. Those women who experienced slight (n = 5,112), moderate (n = 2,158), or extreme (n = 339) downward economic mobility had PTB rates of 6.5, 8.5, and 10.1 %, respectively; RR (95 % CI) = 1.2 (1.0-4.0), 1.6 (1.3-1.9), and 1.9 (1.3-2.6), respectively. Maternal downward economic mobility was also associated with an increased prevalence of biologic, medical, and behavioral risk factors. Interestingly, the relationship between moderate to extreme downward mobility and preterm birth was stronger among former low birth weight (<2500 g, LBW) than non-LBW women: 2.8 (1.4-5.8) versus 1.6 (1.3-1.9), respectively. In multilevel logistic regression models, the adjusted odds ratio of preterm birth for former LBW and non-LBW women who experienced any downward mobility (compared to those women with lifelong upper class status) equaled 2.4 (1.1-5.3) and 1.1 (1.0-1.1), respectively. Downward economic mobility is associated with an increased risk of preterm birth among upper class-born White urban women; this phenomenon is strongest among former low birth weight women.

Movin' on Up: Socioeconomic Mobility and the Risk of Delivering a Small-for-Gestational Age Infant

OBJECTIVE

Poor fetal growth is associated with increased rates of adverse health outcomes in children and adults. The social determinants of poor fetal growth are not well understood. Using multiple socioeconomic indicators measured at the individual level, this study examined changes in maternal socioeconomic position (SEP) from childhood to adulthood (socioeconomic mobility) in relation to poor fetal growth in offspring.

METHODS

Data were from the Pregnancy Outcomes and Community Health Study (September 1998-June 2004) that enrolled women in mid-pregnancy from 52 clinics in five Michigan communities (2463 women: 1824 non-Hispanic White, 639 non-Hispanic Black). Fetal growth was defined by birthweight-for-gestational age percentiles; infants with birthweight-for-gestational age <10th percentile were referred to as small-for-gestational age (SGA). In logistic regression models, mothers whose SEP changed from childhood to adulthood were compared to two reference groups, the socioeconomic group they left and the group they joined.

RESULTS

Approximately, 8.2 % of women (non-Hispanic White: 6.3 %, non-Hispanic Black: 13.9 %) delivered an SGA infant. Upward mobility was associated with decreased risk of delivering an SGA infant. Overall, the SGA adjusted-odds ratio was 0.34 [95 % confidence interval (CI) 0.17-0.69] for women who moved from lower to middle/upper versus static lower class, and 0.44 (CI 0.28-1.04) for women who moved from middle to upper versus static middle class. There were no significant differences in SGA risk when women were compared to the SEP group they joined.

CONCLUSIONS

Our findings support a link between mother's socioeconomic mobility and SGA offspring. Policies that allow for the redistribution or reinvestment of resources may reduce disparities in rates of SGA births.

Association of neighborhood context with offspring risk of preterm birth and low birthweight: A systematic review and meta-analysis of population-based studies

Findings from studies investigating associations of residential environment with poor birth outcomes have been inconsistent. In a systematic review and meta-analysis, we examined associations of neighborhood disadvantage with preterm birth (PTB) and low birthweight (LBW), and explored differences in relationships among racial groups. Two reviewers searched English language articles in electronic databases of published literature. We used random effects logistic regression to calculate odds ratios (and 95% confidence intervals) relating neighborhood disadvantage with PTB and LBW. Neighborhood disadvantage, most disadvantaged versus least disadvantaged neighborhoods, was defined by researchers of included studies, and comprised of poverty, deprivation, racial residential segregation or racial composition, and crime. We identified 1314 citations in the systematic review. The meta-analyses included 7 PTB and 14 LBW cross-sectional studies conducted in the United States (U.S.). Overall, we found 27% [95%CI: 1.16, 1.39] and 11% [95%CI: 1.07, 1.14] higher risk for PTB and LBW among the most disadvantaged compared with least disadvantaged neighborhoods. No statistically significant association was found in meta-analyses of studies that adjusted for race. In race-stratified meta-analyses models, we found 48% [95%CI: 1.25, 1.75] and 61% [95%CI: 1.30, 2.00] higher odds of PTB and LBW among non-Hispanic white mothers living in most disadvantaged neighborhoods compared with those living in least disadvantaged neighborhoods. Similar, but less strong, associations were observed for PTB (15% [95%CI: 1.09, 1.21]) and LBW (17% [95%CI: 1.10, 1.25]) among non-Hispanic black mothers. Neighborhood disadvantage is associated with PTB and LBW, however, associations may differ by race. Future studies evaluating causal mechanisms underlying the associations, and racial/ethnic differences in associations, are warranted.

Race, Age, and Neighborhood Socioeconomic Status in Low Birth Weight Disparities Among Adolescent Mothers: An Intersectional Inquiry

INTRODUCTION

Few studies examined socioeconomic contributors to racial disparities in low birth weight outcomes between African-American and Caucasian adolescent mothers. This cross-sectional study examined the intersections of maternal racial status, age, and neighborhood socioeconomic status in explaining these disparities in low birth weight outcomes across a statewide sample of adolescent mothers.

METHODS

Using data from the North Carolina State Center of Health Statistics for 2010-2011, birth cases for 16,472 adolescents were geocoded by street address and linked to census-tract information from the 2010 United States Census. Multilevel models with interaction terms were used to identify significant associations between maternal racial status, age, and neighborhood socioeconomic status (as defined by census-tract median household income) and low birth weight outcomes across census tracts.

RESULTS

Significant racial differences were identified in which African-American adolescents had greater odds of low birth weight outcomes than Caucasian adolescents (OR=1.88, 95% CI 1.64, 2.15). Although racial disparities in low birth weight outcomes remained significant in context of maternal age and neighborhood socioeconomic status, the greatest disparities were found between African-American and Caucasian adolescents that lived in areas of higher socioeconomic status (p<.001). Maternal age was not significantly associated with racial differences in low birth weight outcomes.

CONCLUSION

These findings indicate that racial disparities in low birth weight outcomes among adolescent mothers can vary by neighborhood socioeconomic status. Further investigations using intersectional frameworks are needed for examining the relationships between neighborhood socioeconomic status and birth outcome disparities among infants born to adolescent mothers.

The role of social determinants in explaining racial/ethnic disparities in perinatal outcomes

In the United States, there continue to be significant racial/ethnic disparities in preterm birth (PTB) rates, infant mortality, and fetal mortality rates. One potential mediator of these disparities is social determinants of health, including individual socioeconomic factors; community factors such as crime, poverty, housing, and the racial/ethnic makeup of the community; and the physical environment. Previous work has identified statistically significant associations between each of these factors and adverse pregnancy outcomes. However, there are recent studies that provide new, innovative insights into this subject, including adding social determinant data to population-based datasets; exploring multiple constructs in their analysis; and examining environmental factors. The objective of this review will be to examine this recent research on the association of each of these sets of social determinants on racial/ethnic disparities PTB, infant mortality, and fetal mortality to highlight potential areas for targeted intervention to reduce these differences.

Maternal and pediatric health and disease: integrating biopsychosocial models and epigenetics

The concepts of allostasis (stability through adaptation) and accumulated life stress (McEwen's allostatic load) aim to understand childhood and adult outcomes. Chronic malnutrition, changes in social condition, and adverse early-life experiences may program phenotypes and contribute to long-lasting disease risk. However, integration of life course approaches, social and economic contexts, and comparison among different biopsychosocial models has not generally been explored. This review critically examines the literature and evaluates recent insights into how environmental stress can alter lifelong hypothalamic-pituitary-adrenal axis and immune system responsiveness and induce metabolic and neurodevelopmental maladaptation. Models of biopsychosocial stress overlap but may consider different conditions. Concepts include allostasis, which incorporates hormonal responses to predictable environmental changes, and Geronimus's "weathering," which aims to explain how socially structured, repeated stress can accumulate and increase disease vulnerability. Weathering emphasizes roles of internalized/interpersonal racism in outcomes disparities. For Mexican immigrants and Mexican Americans, the "acculturation" framework has proven especially useful to explore disparities, including preterm birth and neuropsychiatric risks in childhood. Complexities of stress assessments and recent research into epigenetic mechanisms mediating effects of physical, nutritional, psychological, and social stress are reviewed.

Racial/Ethnic Disparities in Depressive Symptoms Among Pregnant Women Vary by Income and Neighborhood Poverty

We examined racial/ethnic disparities in depressive symptoms during pregnancy among a population-based sample of childbearing women in California (N = 24,587). We hypothesized that these racial/ethnic disparities would be eliminated when comparing women with similar incomes and neighborhood poverty environments. Neighborhood poverty trajectory descriptions were linked with survey data measuring age, parity, race/ethnicity, marital status, education, income, and depressive symptoms. We constructed logistic regression models among the overall sample to examine both crude and adjusted racial/ethnic disparities in feeling depressed. Next, stratified adjusted logistic regression models were constructed to examine racial/ethnic disparities in feeling depressed among women of similar income levels living in similar neighborhood poverty environments. We found that racial/ethnic disparities in feeling depressed remained only among women who were not poor themselves and who lived in long-term moderate or low poverty neighborhoods.

The role of socioeconomic factors in Black-White disparities in preterm birth

OBJECTIVES

We investigated the role of socioeconomic factors in Black-White disparities in preterm birth (PTB).

METHODS

We used the population-based California Maternal and Infant Health Assessment survey and birth certificate data on 10 400 US-born Black and White California residents who gave birth during 2003 to 2010 to examine rates and relative likelihoods of PTB among Black versus White women, with adjustment for multiple socioeconomic factors and covariables.

RESULTS

Greater socioeconomic advantage was generally associated with lower PTB rates among White but not Black women. There were no significant Black-White disparities within the most socioeconomically disadvantaged subgroups; Black-White disparities were seen only within more advantaged subgroups.

CONCLUSIONS

Socioeconomic factors play an important but complex role in PTB disparities. The absence of Black-White disparities in PTB within certain socioeconomic subgroups, alongside substantial disparities within others, suggests that social factors moderate the disparity. Further research should explore social factors suggested by the literature-including life course socioeconomic experiences and racism-related stress, and the biological pathways through which they operate-as potential contributors to PTB among Black and White women with different levels of social advantage.

Does neighborhood deprivation modify the effect of preterm birth on children's first grade academic performance?

Children's cognitive development and academic performance are linked to both fetal and early childhood factors, including preterm birth and family socioeconomic status. We evaluated whether the relationship between preterm birth (PTB) and first grade standardized test performance among Georgia public school students was modified by neighborhood deprivation in early childhood. The Georgia Birth to School cohort followed 327,698 children born in Georgia from 1998 to 2002 through to end-of-year first grade standardized tests. Binomial and log-binomial generalized estimating equations were used to estimate risk differences and risk ratios for the associations of both PTB and the Neighborhood Deprivation Index for the census tract in which each child's mother resided at the time of birth with test failure (versus passing). The presence of additive and multiplicative interaction was assessed. PTB was strongly associated with test failure, with increasing risk for earlier gestational ages. There was positive additive interaction between PTB and neighborhood deprivation. The main effect of PTB versus term birth increased risk of mathematics failure: 15.9% (95%CI: 13.3-18.5%) for early, 5.0% (95% CI: 4.1-5.9%) for moderate, and 1.3% (95%CI: 0.9-1.7%) for late preterm. Each 1 standard deviation increase in neighborhood deprivation was associated with 0.6% increased risk of mathematics failure. For children exposed to both PTB and higher neighborhood deprivation, test failure was 4.8%, 1.5%, and 0.8% greater than the sum of two main effects for early, moderate, and late PTB, respectively. Results were similar, but slightly attenuated, for reading and English/language arts. Our results suggest that PTB and neighborhood deprivation additively interact to produce greater risk among doubly exposed children than would be predicted from the sum of the effects of the two exposures. Understanding socioeconomic disparities in the effect of PTB on academic outcomes at school entry is important for targeting of early childhood interventions.

Epigenetic mechanisms in fetal origins of health and disease

Early life environment predicts future health. The initial precedents and research focus on this concept arose out of historical events. However, this concept continues to be relevant as evidenced by the recent Chinese famine and the evidence of racial disparities in the United States. The latter allows us to introduce the "life course model" and "weathering" as relevant epigenetic phenomena. We then review the molecular components of environmental epigenetics. We subsequently present glucocorticoid receptor biology as a paradigm that involves all of the components. Finally, we suggest that environmental epigenetics are a key component of the future of personalized medicine.

Do in utero events contribute to current health disparities in reproductive medicine?

Health disparities exist in reproductive medicine as discussed in detail in the subsequent articles of this issue; however, in most cases, the exact cause of these differences is unknown. Some of these disparities can be linked to environmental exposures such as alcohol and other hazardous toxic exposures (polycarbonate, pesticides, nicotine) in adults. In addition, low socioeconomic status, behavioral risk factors, and lack of education have been linked to poor obstetric and reproductive outcomes in minority groups. Aside from these various environmental exposures later in life, there is evidence that adverse events in utero could contribute to poor reproductive outcome in specific minority groups. We will focus on the developmental origins of health and disease as a possible causal mechanism for health disparities in reproductive diseases, as this perspective may suggest tractable solutions of how to address and eliminate these health disparities.

Racial and ethnic health disparities in reproductive medicine: an evidence-based overview

Racial and ethnic health disparities in reproductive medicine exist across the life span and are costly and burdensome to our healthcare system. Reduction and ultimate elimination of health disparities is a priority of the National Institutes of Health who requires reporting of race and ethnicity for all clinical research it supports. Given the increasing rates of admixture in our population, the definition and subsequent genetic significance of self-reported race and ethnicity used in health disparity research is not straightforward. Some groups have advocated using self-reported ancestry or carefully selected single-nucleotide polymorphisms, also known as ancestry informative markers, to sort individuals into populations. Despite the limitations in our current definitions of race and ethnicity in research, there are several clear examples of health inequalities in reproductive medicine extending from puberty and infertility to obstetric outcomes. We acknowledge that socioeconomic status, education, insurance status, and overall access to care likely contribute to the differences, but these factors do not fully explain the disparities. Epigenetics may provide the biologic link between these environmental factors and the transgenerational disparities that are observed. We propose an integrated view of health disparities across the life span and generations focusing on the metabolic aspects of fetal programming and the effects of environmental exposures. Interventions aimed at improving nutrition and minimizing adverse environmental exposures may act synergistically to reverse the effects of these epigenetic marks and improve the outcome of our future generations.