Maternal perceived stress and the increased risk of preterm birth in a majority non-Hispanic Black pregnancy cohort

The Maternal and Infant Environmental Health Riskscape study of perinatal disparities in greater Houston: rationale, study design and participant profiles

Introduction

The Maternal and Infant Environmental Health Riskscape (MIEHR) Center was established to address the interplay among chemical and non-chemical stressors in the biological, physical, social, and built environments that disproportionately impact perinatal health among Black pregnant people in a large and diverse urban area with documented disparities in the U.S.

Methods

The MIEHR cohort is recruiting non-Hispanic Black and non-Hispanic white pregnant people who deliver their infants at major obstetric hospitals in Houston, Texas. At enrollment, all participants are asked to provide urine samples for chemical [metals, cotinine, and polycyclic aromatic hydrocarbons (PAHs)] analyses and blood samples. A subset of the cohort is asked to provide oral and vaginal swabs, and fecal samples. Questionnaire and electronic health record data gather information about residential address history during pregnancy, pregnancy history and prenatal care, sociodemographic and lifestyle factors, experiences of discrimination and stress, and sources of social support. Using information on where a participant lived during their pregnancy, features of their neighborhood environment are characterized. We provide summaries of key individual- and neighborhood-level features of the entire cohort, as well as for Black and white participants separately.

Results

Between April 2021 and February 2023, 1,244 pregnant people were recruited. Nearly all participants provided urine samples and slightly less than half provided blood samples. PAH exposure patterns as assessed on 47% of participants thus far showed varying levels depending on metabolite as compared to previous studies. Additionally, analyses suggest differences between Black and white pregnant people in experiences of discrimination, stress, and levels of social support, as well as in neighborhood characteristics.

Discussion

Our findings to date highlight racial differences in experiences of discrimination, stress, and levels of support, as well as neighborhood characteristics. Recruitment of the cohort is ongoing and additional neighborhood metrics are being constructed. Biospecimens will be analyzed for metals and PAH metabolites (urine samples), miRNAs (plasma samples) and the microbiome (oral swabs). Once enrollment ends, formal assessments are planned to elucidate individual- and neighborhood-level features in the environmental riskscape that contribute to Black-White disparities in perinatal health.

Maternal stress and early childhood BMI among US children from the Environmental influences on Child Health Outcomes (ECHO) program

BACKGROUND

We aimed to understand the association between maternal stress in the first year of life and childhood body mass index (BMI) from 2 to 4 years of age in a large, prospective United States-based consortium of cohorts.

METHODS

We used data from the Environmental influences on Child Health Outcomes program. The main exposure was maternal stress in the first year of life measured with the Perceived Stress Scale (PSS). The main outcome was the first childhood BMI percentile after age 2 until age 4 years. We used an adjusted linear mixed effects model to examine associations between BMI and PSS quartile.

RESULTS

The mean BMI percentile in children was 59.8 (SD 30) measured at 3.0 years (SD 1) on average. In both crude models and models adjusted for maternal BMI, age, race, ethnicity, infant birthweight, and health insurance status, no linear associations were observed between maternal stress and child BMI.

CONCLUSIONS

Among 1694 maternal-infant dyads, we found no statistically significant relationships between maternal perceived stress in the first year of life and child BMI after 2 through 4 years.

IMPACT

Although existing literature suggests relationships between parental stress and childhood BMI, we found no linear associations between maternal stress in the first year of life and childhood BMI at 2-4 years of age among participants in ECHO cohorts. Higher maternal stress was significantly associated with Hispanic ethnicity, Black race, and public health insurance. Our analysis of a large, nationally representative sample challenges assumptions that maternal stress in the first year of life, as measured by a widely used scale, is associated with offspring BMI.

Neighborhood Deprivation and Association With Neonatal Intensive Care Unit Mortality and Morbidity for Extremely Premature Infants

Importance

Socioeconomic status affects pregnancy and neurodevelopment, but its association with hospital outcomes among premature infants is unknown. The Area Deprivation Index (ADI) is a validated measure of neighborhood disadvantage that uses US Census Bureau data on income, educational level, employment, and housing quality.

Objective

To determine whether ADI is associated with neonatal intensive care unit (NICU) mortality and morbidity in extremely premature infants.

Design, Setting, and Participants

This retrospective cohort study was performed at 4 level IV NICUs in the US Northeast, Mid-Atlantic, Midwest, and South regions. Non-Hispanic White and Black infants with gestational age of less than 29 weeks and born between January 1, 2012, and December 31, 2020, were included in the analysis. Addresses were converted to census blocks, identified by Federal Information Processing Series codes, to link residences to national ADI percentiles.

Exposures

ADI, race, birth weight, sex, and outborn status.

Main Outcomes and Measures

In the primary outcome, the association between ADI and NICU mortality was analyzed using bayesian logistic regression adjusted for race, birth weight, outborn status, and sex. Risk factors were considered significant if the 95% credible intervals excluded zero. In the secondary outcome, the association between ADI and NICU morbidities, including late-onset sepsis, necrotizing enterocolitis (NEC), and severe intraventricular hemorrhage (IVH), were also analyzed.

Results

A total of 2765 infants with a mean (SD) gestational age of 25.6 (1.7) weeks and mean (SD) birth weight of 805 (241) g were included in the analysis. Of these, 1391 (50.3%) were boys, 1325 (47.9%) reported Black maternal race, 498 (18.0%) died before NICU discharge, 692 (25.0%) developed sepsis or NEC, and 353 (12.8%) had severe IVH. In univariate analysis, higher median ADI was found among Black compared with White infants (77 [IQR, 45-93] vs 57 [IQR, 32-77]; P < .001), those who died before NICU discharge vs survived (71 [IQR, 45-89] vs 64 [IQR, 36-86]), those with late-onset sepsis or NEC vs those without (68 [IQR, 41-88] vs 64 [IQR, 35-86]), and those with severe IVH vs those without (69 [IQR, 44-90] vs 64 [IQR, 36-86]). In a multivariable bayesian logistic regression model, lower birth weight, higher ADI, and male sex were risk factors for mortality (95% credible intervals excluded zero), while Black race and outborn status were not. The ADI was also identified as a risk factor for sepsis or NEC and severe IVH.

Conclusions and Relevance

The findings of this cohort study of extremely preterm infants admitted to 4 NICUs in different US geographic regions suggest that ADI was a risk factor for mortality and morbidity after adjusting for multiple covariates.

The associations of objective and perceived neighborhood disadvantage with stress among pregnant black women

BACKGROUND

Neighborhood disadvantage may impact risk of preterm birth through stress. Few studies have examined how neighborhood disadvantage relates to stress during pregnancy, especially for Black women.

METHODS

Secondary data analysis of 572 women in a prospective cohort in Detroit, MI and Columbus, OH. Participants completed questionnaires including the ROSS Neighborhood Disorder Scale, the crime subscale of the Perceived Neighborhood Scale (PNS), and the Perceived Stress Scale. An objective neighborhood disadvantage index (NDI) was created using principal components analysis after geocoding residential addresses and linking to Census data.

RESULTS

All models used logistic regression. Adjusted for maternal age and annual household income, perceived stress was positively associated with perceived neighborhood disorder (p < .01). In a separate model, perceived neighborhood crime was positively associated with perceived neighborhood disorder (p = .005). In a joint model adjusted for age and income, the association of disorder with stress was similar in magnitude (p < .01) but the association between crime and stress weakened. The NDI was not associated with perceived stress before or after adjustment for confounders.

CONCLUSIONS

Perceived neighborhood disadvantage may capture a different dimension than objective neighborhood disadvantage. Future studies should test stress as a pathway by which neighborhood environment increases risk of preterm birth.

Depression screening may not capture significant sources of prenatal stress for Black women

Exposure to stress during pregnancy, including depression, has a significant impact on maternal health. Black women experience varied stressors that impact pregnancy outcomes. Although the move to engage in universal screening of women for depression is a positive step toward improving women's health, it has been deployed without a comprehensive examination of its utility for capturing exposure to other stressors with known associations with perinatal and neonatal health problems for Black women such as discrimination stress. In the present study, we examine the overlap between several sources of stress and a positive screen on the Edinburgh Postnatal Depression Scale (EPDS) in Black pregnant women. Data were gathered from a study examining the effects of stress on prenatal health (N = 168). Discrimination stress, structural and systemic racism stress, perceived stress, and partner abuse were measured using standardized questionnaires during pregnancy. Using a score of ≥ 13 to indicate probable depression the sensitivity of the EPDS to identify women who experienced high levels of discrimination stress (41.7%), structural and systemic racism (39.5%), perceived stress (63.4%), and partner abuse (45.2%) was suboptimal. Lowering the threshold for a positive screen on the EPDS to a score of 10 improved sensitivity but did not solve the problem of under-identification of women whose health is at risk. The focus on depression screening for pregnant women should be re-considered. A screening toolkit that more rigorously and broadly assesses risk and need for support and intervention is needed to improve perinatal health outcomes for Black women.

Extracellular vesicles are dynamic regulators of maternal glucose homeostasis during pregnancy

Homeostatic regulation of the maternal milieu during pregnancy is critical for maternal and fetal health. The placenta facilitates critical communication between maternal and fetal compartments, in part, through the production of extracellular vesicles (EVs). EVs enable tissue synchrony via cell-cell and long-distance communication and are at their highest circulating concentration during pregnancy. While much work has been done investigating how physiological challenges in pregnancy affect the fetus, the role of placental communication in maternal health has not been well examined. We previously identified placental O-glycosyl transferase (OGT), a glucose-sensing enzyme, as a target of maternal stress where OGT levels and activity affected the O-glycosylation of proteins critical for EV cargo loading and secretion. Here, we hypothesized that placental OGT plays an essential role in maternal homeostatic regulation during pregnancy via its regulation of maternal circulating EV concentrations. Our studies found that changes to key metabolic factors over the circadian cycle, including glucocorticoids, insulin, and glucose, were significantly associated with changes in circulating EV concentration. Targeting placental OGT in mice, we found a novel significant positive relationship between placental OGT and maternal circulating EV concentration that was associated with improving maternal glucose tolerance during pregnancy. Finally, an intravenous elevation in EVs, matching the concentration of EVs during pregnancy, shifted non-pregnant female glucose sensitivity, blunted glucose variance, and improved synchrony of glucose uptake. These data suggest an important and novel role for circulating EVs as homeostatic regulators important in maternal health during pregnancy.

Per- and polyfluoroalkyl substances and psychosocial stressors have a joint effect on adverse pregnancy outcomes in the Atlanta African American Maternal-Child cohort

BACKGROUND

African Americans (AAs) experience high rates of adverse pregnancy outcomes relative to Whites. Differential in utero exposure to environmental chemicals and psychosocial stressors may explain some of the observed health disparities, as exposures to per- and polyfluoroalkyl substances (PFAS) and experiences of discrimination have been linked to adverse birth outcomes. Few studies have examined chemicals and non-chemical stressors together as an exposure mixture, which may better reflect real-life exposure patterns. Here, we adapted methods designed for the analysis of exposure mixtures to examine joint effects of PFAS and psychosocial stress on birth outcomes among AAs.

METHODS

348 participants from the Atlanta African American Maternal-Child cohort were included in this study. Four PFAS were measured in first trimester serum samples. Self-report questionnaires were administered during the first trimester and were used to assess psychosocial stress (perceived stress, depression, anxiety, gendered racial stress). Quantile g-computation and Bayesian kernel machine regression (BKMR) were used to estimate the joint effects between PFAS and psychosocial stressors on gestational age at delivery and birthweight for gestational age z-scores. All models were adjusted for maternal education, maternal age, parity, and any alcohol, tobacco and marijuana use.

RESULTS

Our analytic sample included a socioeconomically diverse group of pregnant women, with 79 % receiving public health insurance. In quantile g-computation models, a simultaneous one-quartile increase in all PFAS, perceived stress, depression, anxiety, and gendered racial stress was associated with a reduction in birthweight z-scores (mean %change per quartile increase = -0.24, 95 % confidence interval = -0.43, -0.06). BKMR similarly showed that increasing all exposures in the mixture was associated with a modest decrease in birthweight z-scores, but not a reduced length of gestation.

DISCUSSION

Using methods designed for analyzing exposure mixtures, we found that a simultaneous increase in in utero PFAS and psychosocial stressors was associated with reduced birthweight for gestational age z-scores.

What is prenatal stress? A scoping review of how prenatal stress is defined and measured within the context of food insecurity, housing instability, and immigration in the United States

BACKGROUND

Stress during pregnancy can lead to significant adverse outcomes for maternal mental health. Early evaluation of prenatal stress can help identify treatment needs and appropriate interventions. Disparities in the social determinants of health can contribute to stress, but what constitutes stress during pregnancy within the social determinants of health framework is poorly understood.

OBJECTIVE

To scope how prenatal stress is defined and measured among pregnant people exposed to three prominent social stressors in the United States: insecurity pertaining to food, housing, and immigration.

ELIGIBILITY CRITERIA

We included all studies that focused on stress during pregnancy in the context of food insecurity, housing instability, and immigration, given their recent policy focus due to the COVID-19 pandemic and ongoing political discourse, in addition to their importance in American College of Obstetricians and Gynecologists (ACOG's) social determinants of health screening tool.

SOURCES OF EVIDENCE

We searched PubMed, Scopus, and Web of Science for articles published between January 2012 and January 2022.

CHARTING METHODS

Using a piloted charting tool, we extracted relevant study information from the selected articles and analyzed the content pertaining to stress.

RESULTS

An initial search identified 1,023 articles, of which 24 met our inclusion criteria. None of the studies defined prenatal stress, and only one used the Prenatal Distress Questionnaire, a prenatal stress-specific tool to measure it. The Perceived Stress Scale was the most common instrument used in seven studies. Fifteen studies measured over 25 alternative exposures that researchers theorized were associated with stress, and 4 of the 15 studies did not explain the association between the measure and stress.

CONCLUSIONS

Our findings demonstrate a fundamental inconsistency in how prenatal stress is defined and measured in the context of social determinants of health, limiting the comparison of results across studies and the potential development of effective interventions to promote better maternal mental health.

Racial disparities in the development of comorbid conditions after preterm birth: A narrative review

Despite recognition and attempts to reduce racial disparities in perinatal outcomes, Black infants are still disproportionately represented among those who are born preterm. Postnatal investigations of racial disparities in comorbidities and outcomes after preterm birth are increasing, although their results and interpretations are conflicting. In the present review, we 1.) identify important methodological limitations of that literature 2.) summarize the conflicting literature investigating racial disparities, specifically Black-white differences, in postnatal comorbidities and outcomes after preterm birth 3.) describe mechanisms by which racism operates to contextualize our understanding to inform future work to actively reduce disparities in preterm birth and subsequently, its complications.