The Intergenerational Impact of Terror: Did the 9/11 Tragedy Impact the Initial Human Capital of the Next Generation?

Selection in utero against male twins in the United States early in the COVID-19 pandemic

OBJECTIVES

We aim to contribute to the literature reporting tests of selection in utero. The theory of reproductive suppression predicts that natural selection would conserve mechanisms, referred to collectively as selection in utero, that spontaneously abort fetuses unlikely to thrive as infants in the prevailing environment. Tests of this prediction include reports that women give birth to fewer than expected male twins, historically among the frailest of infants, during stressful times. The onset of the COVID-19 pandemic in the United States in Spring 2020 demonstrably stressed the population. We test the hypothesis that conception cohorts in gestation at the onset of the pandemic in the United States yielded fewer than expected live male twin births.

METHODS

We retrieved deidentified data on the universe of live births in the United States from the National Center for Health Statistics birth certificate records. We applied Box-Jenkins time-series methods to the twin secondary sex ratio computed for 77 monthly conception cohorts spanning August 2013 to December 2019 to detect outlying cohorts in gestation at the onset of the pandemic.

RESULTS

The twin secondary sex ratio fell below expected values in three conception cohorts (i.e., July, September, and October 2019, all p < .05) exposed in utero to the onset of the pandemic.

CONCLUSIONS

Our results add to prior findings consistent with selection in utero. The role of selection in utero in shaping the characteristics of live births cohorts, especially during the COVID-19 pandemic, warrants further scrutiny.

The local health impacts of natural resource booms

This paper uses novel micro-data on natural resources and administrative health data in Brazil to study how economic booms in minerals affect health at birth. By implementing a reduced-form estimation of shift-share research designs, the identification strategy relies on the exogeneity of global commodity prices to municipality-specific health outcomes. I find that, following changes in international prices, municipalities with historically more endowments have a higher number of premature births and births with low Appearance, Pulse, Grimace, Activity, Respiration scores. The impacts are primarily driven by metallic minerals. Instead, industrial minerals do not appear to have any effect on birth outcomes. Even though booms in metallic minerals generate benefits through resource windfalls-by increasing wealth and generating economic opportunities-the investigation of mechanisms reveals that they also result in costs-due to pollution-which seem to prevail. Hence, some metallic minerals remain a curse more than a blessing.

Birth Outcomes, Health, and Health Care Needs of Childbearing Women following Wildfire Disasters: An Integrative, State-of-the-Science Review

BACKGROUND

The frequency and severity of extreme weather events such as wildfires are expected to increase due to climate change. Childbearing women, that is, women who are pregnant, soon to be pregnant, or have recently given birth, may be particularly vulnerable to the effect of wildfire exposure.

OBJECTIVES

This review sought to systematically assess what is known about birth outcomes, health, and health care needs of childbearing women during and after exposure to wildfires.

METHODS

An integrative review methodology was utilized to enable article selection, data extraction, and synthesis across qualitative and quantitative studies. Comprehensive searches of SCOPUS (including MEDLINE and Embase), CINAHL, PubMed, and Google Scholar identified studies for inclusion with no date restriction. Included studies were independently appraised by two reviewers using the Crowe Critical Appraisal Tool. The findings are summarized and illustrated in tables.

RESULTS

Database searches identified 480 records. Following title, abstract, and full text screening, sixteen studies published between 2012 and 2022 were identified for this review. Eleven studies considered an association between in utero exposure to wildfire and impacts on birth weight and length of gestation. One study reported increased rates of maternal gestational diabetes mellitus and gestational hypertension following exposure; whereas one study reported differences in the secondary sex ratio. Two studies reported higher incidence of birth defects following in utero exposure to wildfire smoke. Three studies reported increased mental health morbidity, and one study associated a reduction in breastfeeding among women who evacuated from a wildfire disaster.

DISCUSSION

Evidence indicates that wildfire exposure may be associated with changes to birth outcomes and increased morbidity for childbearing women and their babies. These effects may be profound and have long-term and wide-ranging public health implications. This research can inform the development of effective clinical and public health strategies to address the needs of childbearing women exposed to wildfire disaster. https://doi.org/10.1289/EHP10544.

Modeling the Likelihood of Low Birth Weight: Findings from a Chicago-Area Health System

OBJECTIVE

This study presents a statistical model of the incidence of low birth weight (LBW) births in a large, Chicago-area hospital system. The study was undertaken to provide a strategic framework for future health system interventions.

METHODS

Administrative and electronic health records were matched to census Zip Code Tabulation Area (ZCTA) household poverty data for 42,681 births in 2016-2019 at seven system hospitals, serving a diverse patient population. A logistic regression model of LBW incidence was estimated to test the independent significance of maternal sociodemographic characteristics after controlling for clinical risk factors.

RESULTS

The incidence of LBW was 6.3% overall but 11.3% among non-Hispanic Black patients as compared to 5.1% among non-Hispanic White patients. LBW incidence ranged from 9.2% for patients from the poorest ZCTA (20% + poor households) compared to 5.6% of patients from the most affluent (< 5% poor) ZCTA. Nulliparous patients, patients with pre-existing chronic conditions, and patients with hypertensive disorders of pregnancy were significantly more likely to have LBW births. After controlling for clinical risk factors and poverty level, non-Hispanic Black patients were still over 80% more likely and to have a LBW birth.

DISCUSSION

Study findings reveal the joint effects of social and clinical risk factors. Findings profile our highest-risk populations for targeted interventions. Promising prenatal care redesign programs include pregnancy patient navigators, home and group visits, eHealth telemonitoring, improved mental health screening, and diversification of the maternity care workforce. Decreasing LBW births should be a national public health policy priority and will require major investments in the most impacted communities.

Reevaluating the Long-Term Impact of In Utero Exposure to the 1918 Influenza Pandemic

Almond (2006) argues that in utero exposure to the 1918 influenza pandemic reduced the 1919 birth cohort's adult socioeconomic status (SES). We show that this cohort came from lower-SES families, which is incompatible with Almond's cohort-comparison identification strategy. The adult SES deficit is reduced after background characteristics are controlled for; it is small and statistically insignificant in models that include household fixed effects. Replicating Almond's state-level dose-response analysis, we find no evidence in census data that influenza exposure reduced adult SES. Evidence from a city-level dose-response analysis on educational attainment using WWII enlistees from 287 cities is mixed.

Declining violence and improving birth outcomes in the US: Evidence from birth certificate data

The decline in crime that occurred in the last decade of the 20th century was one of the most important societal changes in recent US history. In this paper, we leverage the sharp decline in violence that began in the 1990s to estimate the relationship between county-level murder rates and individual-level birth outcomes for Black, Hispanic, and White mothers. Using the FBI's Uniform Crime Reporting data from 1992 to 2002 and individual-level data from more than 30,000,000 US birth certificates, we employ two-way fixed effects models with a rich set of controls to compare births to similar women in the same county who experienced different crime rates during their pregnancies. Elevated murder rates are associated with substantially higher risks of low birth weight for White mothers, low birth weight and small for gestational age among Black mothers, and small for gestational age among Hispanic mothers. Sensitivity analyses show that the existence of confounders that would invalidate these inferences is highly unlikely, suggesting that we have identified causal relationships, even if some uncertainty about the precision of our estimates remains. These findings have potential implications for prenatal and postpartum care, and they add to a growing body of evidence showing that the "Great American Crime Decline" was strongly linked to improved outcomes among groups that experienced the steepest declines in violence.

Whither weathering? The variable significance of age in Black-White low birth weight disparities

This paper uses birth certificate data to provide novel estimates of the age-specific risk of a low birth weight birth (LBW, an infant born weighting <2500 g) for U.S.-born non-Hispanic Black and White mothers, and finds that patterns vary markedly over space and time. Notably, risk of an LBW birth for Black mothers increased much more steeply with age in 1991-94 than in 2014-17. This decline in LBW risks among older Black mothers led to a decline in the Black-White LBW gap of more than half a percentage point. Both patterns and changes were regional; while age gradients on the Black-White LBW gap were lowest in the South in 1991-94, by 2014-17 they had increased in the South and declined in the rest of the country. These descriptive data allow a new examination of hypotheses regarding the causes of age-specific racial LBW gaps. Research has found that racial disparities in a number of health outcomes, including LBW, increase with age, leading some to speculate that this increase is due to the cumulative effects of exposure to disadvantage. The large degree of variability in Black-White LBW disparities suggests that age-specific causes may also play a role. A series of counterfactual trend analyses explore the roles of two specific mechanisms, smoking and hypertension, and compares these to a more fundamental indicator of socioeconomic status: education.

The Impact of Residing in a Gang Territory on Adverse Birth Outcomes: Evidence from Los Angeles

Gang violence remains an ongoing crisis in many communities in the United States. This paper assesses the potential association of gang-occupied neighborhoods with birth outcomes. Adverse birth outcomes serve as a "barometer" of population health, denoting both poor conditions for human development and portending future public health concerns. We draw upon (1) Los Angeles County Vital Statistics Birth Records (2008-2012), (2) GIS information on gang territory boundaries, (3) LA city geo-coded crime data, and (4) the 2010 U.S. Census and 2006-2010 American Community Survey. We find an association between gang-occupied neighborhoods and adverse birth outcomes; however, this association is largely explained by other neighborhood socio-demographic characteristics, crime notwithstanding. We also find that gangland neighborhoods tend to exacerbate the effects of crime for all birth outcomes, but only significantly so for small for gestational age births. Lastly, gang co-residence, crime, and other neighborhood demographics explain a substantial portion of socioeconomic and racial/ethnic disparities in adverse birth outcomes. Gangland neighborhoods appear to be a novel contributor to both population health and health disparities. Future studies should address these relationships in a broad range of metropolitan settings, paying careful attention to causal linkages and moderating effects of gangs and crime.

Political instability and birth outcomes: Evidence from the 1981 military coup in Spain

We study the effect of exposure to political instability in-utero on health at birth. We exploit the coup d'état that took place in Spain on February 23, 1981. Although short-lived and unsuccessful, the event generated stress and fear among the population, especially in areas that had suffered more repression during the Civil War and the recent dictatorship. We follow a difference-in-differences strategy and compare birth outcomes before and after the coup, in areas that were differentially "affected". We find that children who were in utero during the coup in more affected areas were born with significantly lower birth-weight (around 9 g lighter), especially if they were exposed to the coup in the first or second trimester of pregnancy. We contribute to the literature on the effects of maternal stress by focusing on an acute (and relatively common) source of distress that is unlikely to have affected newborn health via other channels.

Avoidable environmental disasters and infant health: Evidence from a mining dam collapse in Brazil

We study the health consequences of one of the largest environmental disasters of the world mining industry, which largely stemmed from regulatory failure. Exploiting the timing and location of the Mariana mine tailings dam collapse in Brazil, we show that in utero exposure to the tragedy significantly reduced birth weight and increased infant mortality. The adverse effects were stronger for infants born to less educated and nonmarried mothers. These findings indicate that poorly enforced environmental regulation may have long-term welfare impacts on local communities.

Does Maternal Depression Undermine Childhood Cognitive Development? Evidence from the Young Lives Survey in Peru

This paper studies the effect of maternal depression on early childhood cognition in Peru, where rates of depression are around 50%. By using an instrumental variables approach, this study exploits variation in the exogeneity of the exposure to shocks during early life to instrument for maternal depression. The empirical strategy exploits a novel longitudinal data-the Young Lives survey-that includes information on cognitive outcomes of children and variation in their mothers' mental health status between rounds of data collection. Results suggest that maternal depression is detrimental to a child's vocabulary at age 5, but effects fade out by age 8. Effects do not vary by maternal education but are significant only for children living in disadvantaged households. Estimations indicate that the presence of a partner worsens the effect of maternal depression on vocabulary development, results that are driven mainly by households with heavy-drinking partners. Our findings make a strong case for recognizing maternal mental health problems as disorders of public health significance and guide maternal and infant health policies in Peru.