The influence of the built environment on adverse birth outcomes

Mapping high-risk clusters and identifying place-based risk factors of mental health burden in pregnancy

Purpose

Despite affecting up to 20% of women and being the leading cause of preventable deaths during the perinatal and postpartum period, maternal mental health conditions are chronically understudied. This study is the first to identify spatial patterns in perinatal mental health conditions, and relate these patterns to place-based social and environmental factors that drive cluster development.

Methods

We performed spatial clustering analysis of emergency department (ED) visits for perinatal mood and anxiety disorders (PMAD), severe mental illness (SMI), and maternal mental disorders of pregnancy (MDP) using the Poisson model in SatScan from 2016 to 2019 in North Carolina. Logistic regression was used to examine the association between patient and community-level factors and high-risk clusters.

Results

The most significant spatial clustering for all three outcomes was concentrated in smaller urban areas in the western, central piedmont, and coastal plains regions of the state, with odds ratios greater than 3 for some cluster locations. Individual factors (e.g., age, race, ethnicity) and contextual factors (e.g., racial and socioeconomic segregation, urbanity) were associated with high risk clusters.

Conclusions

Results provide important contextual and spatial information concerning at-risk populations with a high burden of maternal mental health disorders and can better inform targeted locations for the expansion of maternal mental health services.

Impact of ambient air pollution exposure during pregnancy on adverse birth outcomes: generalized structural equation modeling approach

BACKGROUND

Air pollution and several prenatal factors, such as socio-demographic, behavioural, physical activity and clinical factors influence adverse birth outcomes. The study aimed to investigate the impact of ambient air pollution exposure during pregnancy adjusting prenatal risk factors on adverse birth outcomes among pregnant women in MACE birth cohort.

METHODS

Data for the study was obtained from the Mother and Child in the Environment (MACE) birth cohort study in Durban, South Africa from 2013 to 2017. Land use regression models were used to determine household level prenatal exposure to PM_2.5, SO₂ and NOx. Six hundred and fifty-six births of pregnant females were selected from public sector antenatal clinics in low socio-economic neighbourhoods. We employed a Generalised Structural Equation Model with a complementary log-log-link specification.

RESULTS

After adjustment for potential prenatal factors, the results indicated that exposure to PM_2.5 was found to have both significant direct and indirect effects on the risk of all adverse birth outcomes. Similarly, an increased level of maternal exposure to SO₂ during pregnancy was associated with an increased probability of being small for gestational age. Moreover, preterm birth act a mediating role in the relationship of exposure to PM_2.5, and SO₂ with low birthweight and SGA.

CONCLUSIONS

Prenatal exposure to PM_2.5 and SO₂ pollution adversely affected birth outcomes after controlling for other prenatal risk factors. This suggests that local government officials have a responsibility for better control of air pollution and health care providers need to advise pregnant females about the risks of air pollution during pregnancy.

Using non-parametric Bayes shrinkage to assess relationships between multiple environmental and social stressors and neonatal size and body composition in the Healthy Start cohort

BACKGROUND

Both environmental and social factors have been linked to birth weight and adiposity at birth, but few studies consider the effects of exposure mixtures. Our objective was to identify which components of a mixture of neighborhood-level environmental and social exposures were driving associations with birth weight and adiposity at birth in the Healthy Start cohort.

METHODS

Exposures were assessed at the census tract level and included air pollution, built environment characteristics, and socioeconomic status. Prenatal exposures were assigned based on address at enrollment. Birth weight was measured at delivery and adiposity was measured using air displacement plethysmography within three days. We used non-parametric Bayes shrinkage (NPB) to identify exposures that were associated with our outcomes of interest. NPB models were compared to single-predictor linear regression. We also included generalized additive models (GAM) to assess nonlinear relationships. All regression models were adjusted for individual-level covariates, including maternal age, pre-pregnancy BMI, and smoking.

RESULTS

Results from NPB models showed most exposures were negatively associated with birth weight, though credible intervals were wide and generally contained zero. However, the NPB model identified an interaction between ozone and temperature on birth weight, and the GAM suggested potential non-linear relationships. For associations between ozone or temperature with birth weight, we observed effect modification by maternal race/ethnicity, where effects were stronger for mothers who identified as a race or ethnicity other than non-Hispanic White. No associations with adiposity at birth were observed.

CONCLUSIONS

NPB identified prenatal exposures to ozone and temperature as predictors of birth weight, and mothers who identify as a race or ethnicity other than non-Hispanic White might be disproportionately impacted. However, NPB models may have limited applicability when non-linear effects are present. Future work should consider a two-stage approach where NPB is used to reduce dimensionality and alternative approaches examine non-linear effects.

The public health exposome and pregnancy-related mortality in the United States: a high-dimensional computational analysis

BACKGROUND

Racial inequities in maternal mortality in the U.S. continue to be stark.

METHODS

The 2015-2018, 4-year total population, county-level, pregnancy-related mortality ratio (PRM; deaths per 100,000 live births; National Center for Health Statistics (NCHS), restricted use mortality file) was linked with the Public Health Exposome (PHE). Using data reduction techniques, 1591 variables were extracted from over 62,000 variables for use in this analysis, providing information on the relationships between PRM and the social, health and health care, natural, and built environments. Graph theoretical algorithms and Bayesian analysis were applied to PHE/PRM linked data to identify latent networks.

RESULTS

PHE variables most strongly correlated with total population PRM were years of potential life lost and overall life expectancy. Population-level indicators of PRM were overall poverty, smoking, lack of exercise, heat, and lack of adequate access to food.

CONCLUSIONS

In this high-dimensional analysis, overall life expectancy, poverty indicators, and health behaviors were found to be the strongest predictors of pregnancy-related mortality. This provides strong evidence that maternal death is part of a broader constellation of both similar and unique health behaviors, social determinants and environmental exposures as other causes of death.

Protective Places: the Relationship between Neighborhood Quality and Preterm Births to Black Women in Oakland, California (2007-2011)

Black women have the highest incidence of preterm birth (PTB). Upstream factors, including neighborhood context, may be key drivers of this increased risk. This study assessed the relationship between neighborhood quality, defined by the Healthy Places Index, and PTB among Black women who lived in Oakland, California, and gave birth between 2007 and 2011 (N = 5418 women, N = 107 census tracts). We found that, compared with those living in lower quality neighborhoods, women living in higher quality neighborhoods had 20-38% lower risk of PTB, independent of confounders. Findings have implications for place-based research and interventions to address racial inequities in PTB.

Identifiable Dietary Patterns of Pregnant Women: A Canadian Sample

Purpose: To estimate the percentage of a sample of pregnant women in Canada following a vegetarian, vegan, low-carbohydrate, gluten-free, Mediterranean, or well-balanced diet, before and during pregnancy and to explore if pregnant women received and were satisfied with nutrition information received from health care providers (HCPs).Methods: Participants were conveniently sampled through Facebook and Twitter. An online survey collected data on sociodemographic characteristics, maternal diet, and whether women received and were satisfied with nutrition information from their HCPs. The McNemar test assessed changes in the proportion of diets followed before and during pregnancy.Results: Of 226 women, most followed a well-balanced diet before (76.9%) and during (72.9%) pregnancy (p = 0.26). Vegetarian, gluten-free, vegan, and low-carbohydrate diets were the least followed diets before and during pregnancy (vegetarian: 7.6% vs 5.3%; gluten-free: 4.9% vs 4.0%; vegan: 2.7% vs 2.2%; low-carbohydrate:4.0% vs 0.4%). Overall, the number of women following restrictive diets before pregnancy was significantly reduced throughout pregnancy (19.1% vs 12.0%, p < 0.001). Only 52.0% of women received nutrition information from their primary HCP, and 35.6% were satisfied with the nutrition information received.Conclusions: Most women followed a well-balanced diet before and during pregnancy and approximately one-third were satisfied with the information received from HCPs.

Effects of prenatal oral L-arginine on birth outcomes: a meta-analysis

Adverse birth outcomes are associated with elevated mortality and morbidity rates throughout life. This meta-analysis of randomised controlled trials examined whether prenatal oral L-arginine has effects on birth outcomes. A total of 45 overall good quality studies were extracted from 10 finally eligible articles. In comparison to controls, providing oral L-arginine to women with a history of poor pregnancy outcomes significantly reduced risks of intrauterine growth retardation neonates, pre-term birth and respiratory distress syndrome (n = 7, 3 and 3, respectively) and significantly increased birthweight and gestational age (n = 8 and 5, respectively) L-Arginine significantly increased Apgar score in women at high risk of pre-eclampsia or with pre-eclampsia or gestational or mild chronic hypertension in comparison to controls (n = 4). L-Arginine showed no significant effect on any other outcome examined (n = 2). The quality of evidence was at least medium or high. Consequently, oral L-arginine may be at least moderately recommended for women with a history of poor pregnancy outcomes and at high risk of pre-eclampsia or with pre-eclampsia or gestational or mild chronic hypertension. However, further studies are required to provide stronger conclusions, partly due to small study effects.

Social Determinants of Health and Adverse Outcomes in Adolescent Pregnancies

The association between adolescent childbearing and adverse maternal and birth outcomes has been well documented. Adverse adolescent pregnancy outcomes are associated with substantial risk of long-term morbidities for the young mother and their newborns. Multiple levels of social disadvantage have been related to adverse pregnancy outcomes among adolescent mothers. Patterns of cumulative social adversity define the most marginalized group of adolescents at the highest risk of experiencing adverse maternal and birth outcomes. Using a social determinants of health (SDOH) framework, we present an overview of the current scientific evidence on the influence of these conditions on adolescent pregnancy outcomes. Multiple SDOH such as residence in remote areas, low educational attainment, low socioeconomic status, and lack of family and community support have been linked with increased risk of adverse pregnancy outcomes among adolescents. Based on the PROGRESS-Plus equity framework, this review highlights some SDOH aspects that perinatal health researchers, clinicians, and policy makers should consider in the context of adolescent pregnancies. There is a need to acknowledge the intersectional nature of multiple SDOH when formulating clinical and societal interventions to address the needs of the most marginalized adolescent in this critical period of life.

Prenatal Exposure to Favorable Social and Environmental Neighborhood Conditions Is Associated with Healthy Pregnancy and Infant Outcomes

Neighborhood and individual level risks commonly co-occur for pregnant women and may cumulatively contribute to birth outcomes. Moreover, the relationship between favorable social and environmental neighborhood conditions and perinatal outcomes has been understudied. This study considered the accumulated impact of prenatal exposure to positive neighborhood social, environmental, and educational conditions in relation to maternal health during pregnancy and birth size outcomes. In a prospective study of a multi-ethnic and socioeconomically diverse cohort (n = 239) of pregnant women and their infants, neighborhoods were characterized by the Child Opportunity Index (COI), a census-tract composite indicator representing favorable social, environmental, and educational community conditions. Adjusted generalized estimating equations showed that favorable neighborhood conditions promoted the growth of longer and heavier infant bodies, and reduced the risk of intrauterine growth restriction. The associations were stronger for female versus male infants, though not significantly different. Moreover, COI was associated with better maternal mental health and diet during pregnancy; diet significantly mediated the association between COI and birth size outcomes. This study underscores the importance of considering the accumulated benefit of neighborhood assets for maternal and infant health. Interventions that capitalizes on the full range of contextual assets in which mothers live may promote pregnancy health and fetal growth.

Landscapes of becoming social: A systematic review of evidence for associations and pathways between interactions with nature and socioemotional development in children

BACKGROUND

Existing research indicates that spending time in nature is associated with diverse aspects of children's health and wellbeing. Although fundamental to later life chances and health, no systematic reviews, to our knowledge, have focused specifically on the effects of interaction with nature on socioemotional functioning in childhood.

OBJECTIVES

Amongst children, what is the consistency of associations between the availability of or spending time in nature on socioemotional function and development? Furthermore, which child behaviours and states independently associate with socioemotional function and availability of or spending time in nature, and what is the consistency of associations between these behaviours and states and contact with nature?

DATA SOURCES

Embase, Environment Complete, MEDLINE, and APA PsycINFO. Eligible studies were backward and forward snowball-searched.

STUDY ELIGIBILITY CRITERIA

Studies investigating effects of, or associations between, availability of or interaction with nature on socioemotional or proximal outcomes in children under the age of 12 years were included in this review.

STUDY APPRAISAL AND SYNTHESIS METHODS

The internal validity of studies investigating socioemotional outcomes were based on assessments of elements of study design, conduct, and reporting to identify potential issues related to confounding or other biases. The number of analyses indicating positive, negative, and non-significant associations between availability or interaction with green space and the outcomes were summed.

RESULTS

A total of 223 eligible full-texts, of which 43 pertained to socioemotional outcomes and 180 to proximal outcomes, met eligibility criteria. Positive associations between availability of and spending time in green space were found with children's intra- and interpersonal socioemotional function and development. Proportions of positive findings ranged from 13.9% to 55% across experimental and observational research, exposures, populations, and contexts. Modifying and mediating factors were identified. We found consistent evidence for improved aspects of cognition and, for children over six years, reduced risk of obesity and overweight in association with green space; consistent links between movement behaviours in the experimental, but not observational research; tentative trends suggesting associations with play, motor skills, language, screen time, and communication skills; little evidence for positive associations between green space and mood, physical wellbeing, and stress; some evidence for associations with healthy birth outcomes, and little evidence for direct associations between availability of green space and asthma and allergy prevalence, however, mediation via, for example, air pollution was likely.

LIMITATIONS

We identified few studies without either probable or severe risk of bias in at least one item. Improved study quality may therefore result in different results. Restricting analyses to include only studies considered at low risk of bias indicated similar or slightly lower proportions of positive findings. Risk of bias in proximal outcomes was not assessed.

CONCLUSIONS

The empirical evidence for benefits of availability of and interaction green space for child socioemotional function and development must currently be considered limited. A number of proximal indicators were identified. Systematic review registration number.

PROSPERO ID

CRD42019135016.

Space-time hot spots of critically ill small for gestational age newborns and industrial air pollutants in major metropolitan areas of Canada

We assessed the association of spatiotemporal hot spots of critically ill small for gestational age (ciSGA) newborns and industrial air emissions. Using neonatal admission data from the Canadian Neonatal Network between 2006 and 2010 (n = 32,836 infants), we aggregated maternal residential postal codes from nineteen census metropolitan areas (CMA) into space-time cubes and applied emerging hot spot analyses. Using National Pollutant Release Inventory data (n = 161 chemicals) and Environment Canada weather station data (n = 19 sites), we estimated monthly wind-dispersion of air emissions and calculated hot spots. We associated the patterns using logistic regression, with covariates for low socioeconomic status, NO₂ pollution, and number of infants. A total of 5465 infants were identified as ciSGA and the larger CMAs had more and larger hot spots (i.e. accumulation of events in space and time). Seventy-eight industrial chemical hot spots were associated with ciSGA hot spots. The highest number of positive associations were for 28 different pollutants, which differed by CMA. Twenty-one were known or suspected developmental toxicants, such as particulate matter, carbon monoxide, heavy metals, and volatile organic compounds. Associations with hot spots of industrial chemical emissions were geographically specific and may help explain the space-time trends of ciSGA.

Effectiveness of Prenatal Lipid-Based Nutrient Supplementation to Improve Birth Outcomes: A Meta-analysis

This study was performed to examine whether prenatal lipid-based nutrient supplementation is an effective means of improving birth outcomes compared with other types of supplementation including iron folic acid (IFA), United Nations multiple micronutrient preparation (UNIMAP), other multiple micronutrients (MMN), and fortified corn-soy blend (CSB). A meta-analysis was performed to determine the relative risks and mean differences in birth outcomes between prenatal lipid-based nutrients versus prenatal IFA, UNIMAP, other MMN, and CSB in randomized controlled trials. Eleven databases, including PubMed (MEDLINE), were searched. Study quality was assessed using the Cochrane Collaboration's tool for assessing the risk of bias. Fifty-eight overall good-quality studies extracted from 11 eligible articles with 101,553 mother-baby pairs were included. Lipid-based nutrient supplementation significantly reduced the risks of low birthweight, small for gestational age, and stunting (n = 5, 5, and 4, respectively) and significantly increased the means of birthweight, birth length, arm circumference, and weight-for-age z-score (n = 5, 5, 4, and 3, respectively). Lipid-based nutrient supplementation did not significantly reduce the risk of preterm birth, stillbirth, abortion, perinatal death, or underweight (n = 5, 5, 5, 3, or 3, respectively) or significantly increase the mean of head circumference or height-for-age z-score (n = 4 or 2, respectively). In conclusion, the results supported the efficacy of prenatal lipid-based nutrient supplementation compared with IFA, UNIMAP, other MMN, and CSB for reducing the risk of small birth size.

Preterm birth disparities between states in the United States: an opportunity for public health interventions

Objective: To examine associations between statelevel characteristics and state-level preterm birth rates.Study design: We conducted a retrospective ecological cross-sectional study using statelevel data from 2013 to 2014 extracted from publicly available sources -the March of Dimes PeriStats database, the U.S. Census Bureau, the US Department of Education, and the US Department of Justice.Results: State-level preterm birth rates correlated with the following state characteristics: poverty rate, obesity rate, percentage of non-Hispanic Black women residents, smoking rate, percent of C - section deliveries, percent of births to women <20 years old, pregnancies receiving late/no prenatal care, and violent crimes per capita. Linear regression analysis found that only the percent of non-Hispanic Black women by state remained a significant predictor of state-level preterm birth rates after adjusting for other risk factors.Conclusions: States with higher percentages of non-Hispanic Black women had higher rates of preterm birth, even after adjusting for sociodemographic characteristics, prenatal care, and maternal health by state. These findings suggest that public health interventions that target contextual and environmental risk factors affecting non-Hispanic Black women may help to curb rising rates of preterm birth in the United States.

Geospatial analyses of adverse birth outcomes in Southwestern Ontario: Examining the impact of environmental factors

BACKGROUND

A growing body of research has examined the association between exposure to environmental factors during pregnancy and adverse birth outcomes; however, many studies do not control for potential covariates and findings vary considerably.

OBJECTIVE

To test the relative influence of environmental factors including exposure to air pollution, major roads, highways, industry, parks, greenspaces, and food retailers on low birth weight (LBW) and preterm birth (PTB) in Southwestern Ontario (SWO), Canada, while accounting for medical (e.g., previous preterm birth, gestational diabetes), behavioral (e.g., alcohol, smoking), demographic (e.g., maternal age, body mass index), and neighborhood-level socioeconomic (e.g., household income, education) factors.

METHODS

This retrospective cohort study consisted of a large sample of pregnant women from SWO who gave birth to singleton newborns between February 2009 and February 2014 at London Health Sciences Centre. Data on maternal postal codes were entered into a Geographic Information System to map the distribution of maternal residences and determine selected characteristics of their neighborhood environments (i.e., socioeconomic, built, natural). These variables were developed based on postal codes where the mothers lived prior to giving birth. Logistic regression was used to assess the relative effects of the physical environment, socioeconomic status, clinical history, and behavioral risk factors on mothers having a LBW or PTB infant.

RESULTS

Out of 25,263 live births, 5.7% were LBW and 7.5% were PTB. Exposure to sulfur dioxide was a top predictor of both LBW and PTB. For every one-unit increase in sulfur dioxide, the odds of a LBW and PTB were 3.4 (95% CI: 2.2, 5.2) and 2.0 (95% CI: 1.4, 3.0) times higher, after controlling for other variables in the model, respectively (p < 0.001). Previous PTB was also highly associated with both birth outcomes.

CONCLUSIONS

Health care providers should be informed about the hazards of air pollution to developing fetuses so that recommendations can be made to their pregnant patients about limiting exposure when air quality is poor.

Antenatal depression and offspring health outcomes

Background

Depression is the most common mental disorder during pregnancy, with prevalence rates between 4% and 20%. The objective of this review was to synthesize the literature on the association between antenatal depression and offspring birth outcomes, as well as developmental, behavioral, and psychiatric outcomes.

Methods

A search of PubMed, Cochrane, and Medline databases was conducted for articles published until December 2017. Articles focusing on the effects of antenatal depression on the offspring were selected to be reviewed. Reference lists of all studies were examined for any missed articles. A total of 32 articles were included in this review.

Results

Antenatal depression is associated with preterm birth, excessive infant crying, and offspring mental health problems. Untreated antenatal depression is strongly associated with adverse effects on the infant nervous system.

Conclusion

Antenatal depression increases the likelihood of poor offspring health outcomes. Research should investigate whether medication use confounds this relationship.

Spatiotemporal Patterns of Small for Gestational Age and Low Birth Weight Births and Associations With Land Use and Socioeconomic Status

In addition to small for gestational age (SGA) and low birth weight at term (LBWT), critically ill cases of SGA/LBWT are significant events from outcomes and economic perspectives that require further understanding of risk factors. We aimed to assess the spatiotemporal distribution of locations where there were consistently higher numbers of critically ill SGA/LBWT (hot spots) in comparison with all SGA/LBWT and all births. We focused on Edmonton (2008-2010) and Calgary (2006-2010), Alberta, and used a geographical information system to apply emerging hot spot analysis, as a new approach for understanding SGA, LBWT, and the critically ill counterparts (ciSGA or ciLBWT). We also compared the resulting aggregated categorical patterns with proportions of land use and socioeconomic status (SES) using Spearman correlation and logistic regression. There was an overall increasing trend in all space-time clusters. Whole period emerging hot spot patterns among births and SGA generally coincided, but SGA with ciSGA and LBWT with ciLBWT did not. Regression coefficients were highest for low SES with SGA and LBWT, but not with ciSGA and ciLBWT. Open areas and industrial land use were most associated with ciLBWT but not with ciSGA, SGA, or LBWT. Differences in the space-time hot spot patterns and the associations with ciSGA and ciLBWT indicate further need to research the interplay of maternal and environmental influences. We demonstrated the novel application of emerging hot spot analysis for small newborns and spatially related them to the surrounding environment.