Integrative Review of Pregnancy and Birth Outcomes After Exposure to a Hurricane

Hurricane Harvey and the risk of spontaneous preterm and early-term birth

Background

Hurricane Harvey made landfall in August 2017 and resulted in catastrophic flooding in Houston, Texas. Prior studies of hurricanes and preterm birth have found conflicting results. We tested the hypotheses that exposure to Hurricane Harvey was associated with a higher risk of spontaneous pre- and early-term birth and assessed vulnerable subpopulations.

Methods

We conducted a retrospective study of singleton births using administrative birth records in the nine-county greater Houston area from 2015 to 2019. We estimated the likelihood of pre- and early-term births using logistic regression, comparing births occurring during or within 1, 2, or 4 weeks of Hurricane Harvey to unexposed reference periods encompassing the same dates 2 years prior and after. Stratified models assessed effect modification by degree of flooding, birth parent age, high- vs. low-risk pregnancy, race/ethnicity, and prenatal care.

Results

Among 15,564 births, we found no association between exposure to Hurricane Harvey and spontaneous preterm birth within 1 week adjusted (odds ratio [OR], 1.06; 95% confidence interval [CI] = 0.91, 1.25) but a 14% higher odds of spontaneous early-term birth (OR, 1.14; 95% CI = 1.04, 1.25). The odds of early-term birth were even higher in neighborhoods with severe flooding (OR, 1.21; 95% CI = 1.05, 1.38), segregated neighborhoods (OR, 1.23; 95% CI = 1.03, 1.47), and among foreign-born Hispanics (OR, 1.21; 95% CI = 1.04, 1.53) and pregnant people receiving no prenatal care (OR, 1.37; 95% CI = 1.03, 1.82). Effect estimates were attenuated or null when considering 2-week or 4-week lags to define exposure.

Conclusions

Hurricane Harvey was associated with higher odds of spontaneous early-term birth up to 1 week later, especially among socially marginalized populations.

Climate Change and Children's Health: Building a Healthy Future for Every Child

Observed changes in temperature, precipitation patterns, sea level, and extreme weather are destabilizing major determinants of human health. Children are at higher risk of climate-related health burdens than adults because of their unique behavior patterns; developing organ systems and physiology; greater exposure to air, food, and water contaminants per unit of body weight; and dependence on caregivers. Climate change harms children through numerous pathways, including air pollution, heat exposure, floods and hurricanes, food insecurity and nutrition, changing epidemiology of infections, and mental health harms. As the planet continues to warm, climate change's impacts will worsen, threatening to define the health and welfare of children at every stage of their lives. Children who already bear higher burden of disease because of living in low-wealth households and communities, lack of access to high quality education, and experiencing racism and other forms of unjust discrimination bear greater risk of suffering from climate change hazards. Climate change solutions, advanced through collaborative work of pediatricians, health systems, communities, corporations, and governments lead to immediate gains in child health and equity and build a foundation for generations of children to thrive. This technical report reviews the nature of climate change and its associated child health effects and supports the recommendations in the accompanying policy statement on climate change and children's health.

Natural disasters resulting from climate change: The impact of hurricanes and flooding on perinatal outcomes

Although the earth's climate has been continuously changing over billions of years, human influence has accelerated that rate of change. While high latitudes suffer the greatest increase in incremental temperature, moderate latitudes are highly vulnerable due to their temperate/tropical rain storms and hurricanes that bring about extreme flooding events. We and others have shown that there is a link between the occurrence and severity of these climate events and risk of adverse perinatal outcomes. In this review, we will discuss the data and consider interacting near and intermediate sequelae of worsening natural disasters-including food scarcity, disrupted or compromised built environments and infrastructure, and loss of communities with human migration. While certainly tackling these and other proximal mediators of adverse perinatal outcomes will benefit maternal and child health, a failure to meaningfully address the root causes of climate change and resultant environmental chemical exposures will be of little long-term benefit.

A Difference-In Difference Analysis of the South Carolina 2015 Extreme Floods and the Association with Maternal Health

Research documenting the public health impacts of natural disasters often focuses on adults and children. Little research has examined the influence of extreme events, like floods, on maternal health, and less has examined the effect of disasters on maternal indicators like severe maternal morbidity (SMM) or unexpected outcomes of labor and delivery that result in significant short-or long-term consequences to a woman's health. The aim of this study is to identify the impacts of the 2015 flood events on maternal health outcomes in South Carolina, USA. We employ a quasi-experimental design using a difference-in-difference analysis with log-binomial regressions to evaluate maternal outcomes for impacted and control locations during the disaster event. Unlike previous studies, we extended our difference-in-difference analysis to include a trimester of exposure to assess the timing of flood exposure. We did not find evidence of statistically significant main effects on maternal health from the 2015 flood events related to preterm birth, gestational diabetes, mental disorders of pregnancy, depression, and generalized anxiety. However, we did find a statistically significant increase in SMM and low birth weight during the flood event for women in select trimester periods who were directly exposed. Our work provides new evidence on the effects of extreme flood events, like the 2015 floods, which can impact maternal health during specific exposure periods of pregnancy. Additional research is needed across other extreme weather events, as the unique context of the 2015 floods limits the generalizability of our findings.

Human fertility after a disaster: a systematic literature review

Fertility is a key demographic parameter influenced by disaster. With the growing risk of disasters, interest in the fertility response to a disaster is increasing among the public, policy makers and researchers alike. However, a systematic literature review on how disaster affects live birth counts does not yet exist. We reviewed 50 studies retrieved from a systematic search based on a pre-registered protocol. We found an overall negative impact of disasters on fertility. If any, increases in fertility were mostly linked with weather-related physical disasters. We also identified 13 distinct mechanisms which researchers have considered as underlying the fertility effects of disaster. By contrast to the common belief that disasters are more likely to increase fertility in contexts with already high fertility, we found little evidence to suggest that the total fertility rate of the studied populations was an important predictor of the direction, timing or size of fertility impacts. While this may be because no relationship exists, it may also be due to biases we observed in the literature towards studying high-income countries or high-cost disasters. We summarize the methodological limitations identified from the reviewed studies into six practical recommendations for future research. Our findings inform both the theories behind the fertility effects of disasters and the methods for studying them.

Climate change and the adverse impact on the health and well-being of women and girls from the Women's Health Expert Panel of the American Academy of Nursing

Climate change has measurable adverse impact on the general and reproductive health of women and girls. Multinational government organizations, private foundations, and consumer groups identify anthropogenic disruptions in social and ecological environments as the primary threats to human health this century. Drought, micronutrient shortage, famine, mass migration, conflict over resources, and effects on mental health resulting from displacement and war are challenging effects to manage. The most severe effects will be felt by those with the least resources to prepare for and adapt to changes. Climate change is a phenomenon of interest to women's health professionals because women and girls are more vulnerable to the effects due to a combination of physiologic, biologic, cultural, and socioeconomic risk factors. Nurses, with our scientific foundation, human-centered approach, and position of trust in societies can be leaders in efforts at mitigation, adaptation, and building resilience in response to changes in our planetary health.

Severe cyclones and sex-specific birth outcomes in Queensland, Australia: An interrupted time-series analysis

OBJECTIVES

A male is less adaptable to biological stressors than a female fetus with consequent higher morbidity and mortality. Adverse birth outcomes increase and male livebirths decrease after environmental disasters, economic crises, and terrorist events. We hypothesized the ratio of male to female livebirths would decrease in areas affected by severe tropical cyclones (TCs) in Queensland, Australia. Additionally, in male livebirths, there would be an increase in preterm and low birthweight births. Lastly, we hypothesized that the pregnancy stage at which exposure occurred would modify the association between TC exposure and observed outcomes.

METHODS

Interrupted time series analysis was used to analyze Queensland administrative birth records from July 2007 to June 2018 for significant changes in the sex ratio at birth, measured as the proportion of male livebirths. Adjusted generalized linear models were fitted to births in areas affected by two category five TCs: cyclones Yasi (February 2011) and Marcia (February 2015). To explore male mortality and morbidity risk, additional analysis was conducted on the proportion of male stillborn, low birthweight, and preterm births. The association between estimated pregnancy stage during the TC and the proportion of male births was also analyzed.

RESULTS

Contrary to our hypothesis, increases in the proportion of male livebirths were observed following early-pregnancy exposure to cyclone Yasi and mid-pregnancy exposure to Marcia, although the latter was not statistically significant. No significant changes were observed in proportions of male stillborn, low birthweight, and preterm births.

CONCLUSIONS

This study found a significant association between severe TCs and sex ratio at birth. The stage of pregnancy at which maternal stressors were experienced modified this association. Among people exposed in early to mid-pregnancy, the proportion of male births was higher. This may be because of differential loss of females in utero. Studying sex differences in birth outcomes provides insight into in utero vulnerabilities associated with environmental stressors. Climate change is increasing the intensity and frequency of natural disasters. Understanding fetal vulnerability to environmental stressors will provide crucial information supporting early life health interventions that mitigate the immediate and long-term effects.

Experiences of pregnant women exposed to Hurricanes Irma and Maria in the US Virgin Islands: a qualitative study

INTRODUCTION

Hurricanes Irma and Maria made landfall in the US Virgin Islands (USVI) in 2017. To date, there is no published literature available on the experiences of pregnant women in the USVI exposed to these hurricanes. Understanding how hurricanes affect pregnant women is key to developing and executing targeted hurricane preparedness and response policies. The purpose of this study was to explore the experiences of pregnancy and birth among women in the USVI exposed to Hurricanes Irma and Maria.

METHODS

We employed a qualitative descriptive methodology to guide sampling, data collection, and analysis. Semi-structured interviews of 30-60 min in length were conducted with a purposive sample of women (N = 18) in the USVI who were pregnant during or became pregnant within two months after the hurricanes. Interviews were transcribed verbatim and data managed in MAXQDA. Team members developed a codebook, applied codes for content, and reconciled discrepancies. We thematically categorized text according to a socioecological conceptual framework of risk and resilience for maternal-neonatal health following hurricane exposure.

RESULTS

Women's experiences were organized into two main categories (risk and resilience). We identified the following themes related to risk at 3 socioecological levels including: (1) individual: changes in food access (We had to go without) and stress (I was supposed to be relaxing); (2) household/community: diminished psychosocial support (Everyone was dealing with their own things) and the presence of physical/environmental hazards (I was really scared); and (3) maternity system: compromised care capacity (The hospital was condemned). The themes related to resilience included: (1) individual: personal coping strategies (Being calm); (2) household/community: mutual psychosocial and tangible support (We shared our resources); and (3) the maternity system: continuity of high-quality care (On top of their game).

CONCLUSIONS

A socioecological approach provides a useful framework to understand how risk and resilience influence the experience of maternal hurricane exposure. As the frequency of the most intense hurricanes is expected to increase, clinicians, governments, and health systems should work collaboratively to implement hurricane preparedness and response plans that address pregnant women's unique needs and promote optimal maternal-infant health.

Association between severe cyclone events and birth outcomes in Queensland, Australia, 2008-2018: a population based retrospective cohort study

OBJECTIVE

Investigate an association between severe tropical cyclones (TCs) and birth outcomes in an Australian population.

METHODS

We analysed over 600,000 singleton livebirths collected through the Queensland Perinatal Data Collection between 2008 and 2018. We estimated the odds ratios (ORs) of adverse birth outcomes using logistic multi-level modelling.

RESULTS

Exposure to TCs in early pregnancy was associated with significantly higher odds of preterm births in affected compared to unaffected areas during the TC year [OR=1.28, 95%CI=1.11, 1.49, p=0.001] and slightly significant higher odds in affected areas during TC years compared to non-TC years. Significantly higher odds of low birthweight births were associated with mid-pregnancy exposure to cyclone Marcia [OR=1.62, 95%CI=1.00, 2.40, p=0.016] .

CONCLUSIONS

Findings aligned with studies demonstrating an association between exposure to environmental stressors in early to mid-pregnancy and adverse birth outcomes.

IMPLICATIONS FOR PUBLIC HEALTH

There is limited research into TCs and perinatal health in Australia despite most of the population residing along coastlines and TCs presenting one of the nation's most devastating weather events. This study will inform public health practice and contribute to further research into mitigating environmental risks faced by pregnant women.

The Changing Climate and Pregnancy Health

Purpose of Review

Climate change is the biggest public health threat of the twenty-first century but its impact on the perinatal period has only recently received attention. This review summarizes recent literature regarding the impacts of climate change and related environmental disasters on pregnancy health and provides recommendations to inform future adaptation and mitigation efforts.

Recent Findings

Accumulating evidence suggests that the changing climate affects pregnancy health directly via discrete environmental disasters (i.e., wildfire, extreme heat, hurricane, flood, and drought), and indirectly through changes in the natural and social environment. Although studies vary greatly in design, analytic methods, and assessment strategies, they generally converge to suggest that climate-related disasters are associated with increased risk of gestational complication, pregnancy loss, restricted fetal growth, low birthweight, preterm birth, and selected delivery/newborn complications. Window(s) of exposure with the highest sensitivity are not clear, but both acute and chronic exposures appear important. Furthermore, socioeconomically disadvantaged populations may be more vulnerable.

Summary

Policy, clinical, and research strategies for adaptation and mitigation should be continued, strengthened, and expanded with cross-disciplinary efforts. Top priorities should include (a) reinforcing and expanding policies to further reduce emission, (b) increasing awareness and education resources for healthcare providers and the public, (c) facilitating access to quality population-based data in low-resource areas, and (d) research efforts to better understand mechanisms of effects, identify susceptible populations and windows of exposure, explore interactive impacts of multiple exposures, and develop novel methods to better quantify pregnancy health impacts.

Natural disasters and missing children

Using an exogenous measure of natural disasters based on physical intensities, I examine their impact on child mortality. I find that children, mostly, in poor countries are affected - a one standard deviation increase in the natural disaster index leads to an additional 6.77 deaths per 1000 live births in the disaster year. The impact is long lasting, extending beyond the disaster year. I provide suggestive evidence of the potential mechanisms driving these effects, namely, lower GDP and vaccination rates among children, along with an increased maternal mortality and disease incidence in low-income countries due to disasters. Using an endogenous measure of disasters based on damage records from insurance data leads to severe underestimation of the disaster impact. The results are robust to the use of mortality rates from multiple sources, different functional forms, and an extensive dynamic panel specification as well as various other tests.

Trajectories of perinatal depressive symptoms in the context of the COVID-19 pandemic

This study sought to advance understanding of the potential long‐term consequences of the COVID‐19 pandemic for child development by characterizing trajectories of maternal perinatal depression, a common and significant risk factor for adverse child outcomes. Data came from 393 women (86% White, 8% Latina; mean age = 33.51 years) recruited during pregnancy (n = 247; mean gestational age = 22.94 weeks) or during the first year postpartum (n = 146; mean child age = 4.50 months; 55% female). Rates of depression appear elevated, relative to published reports and to a pre‐pandemic comparison group (N = 155). This study also provides evidence for subgroups of individuals who differ in their depressive symptom trajectories over the perinatal period. Subgroup membership was related to differences in maternal social support, but not to child birth outcomes.