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.

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.

The impact of residential greenness on psychological distress among Hurricane Katrina survivors

Residential greenness may support mental health among disaster-affected populations; however, changes in residential greenness may disrupt survivors' sense of place. We obtained one pre- and three post-disaster psychological distress scores (Kessler [K]-6) from a cohort (n = 229) of low-income mothers who survived Hurricane Katrina in New Orleans, Louisiana, USA. Greenness was assessed using average growing season Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) in the 300 m around participants' homes at each time point. We used multivariable logistic regressions to evaluate two hypotheses: 1) that cross-sectional greenness (above vs. below median) was associated with reduced psychological distress (K6≥5); and 2) that changes in residential greenness were associated with adverse mental health. When using EVI, we found that a change in level of greenness (i.e., from high to low [high-low], or from low to high [low-high] greenness, comparing pre- and post-Katrina neighborhoods) was associated with increased odds of distress at the first post-storm survey, compared to moving between or staying within low greenness neighborhoods (low-high odds ratio [OR] = 3.48; 95% confidence interval [CI] = 1.40, 8.62 and high-low OR = 2.60; 95% CI: 1.05, 6.42). Results for NDVI were not statistically significant. More research is needed to characterize how residential greenness may impact the health of disaster survivors, and how these associations may change over time.

Remotely sensed measures of Hurricane Michael damage and adverse perinatal outcomes and access to prenatal care services in the Florida panhandle

BACKGROUND

Studies of effects of hurricanes on perinatal outcomes often rely on approximate measures of exposure. This study aims to use observed damage from aerial imagery to refine residential building damage estimates, evaluate the population changes post landfall, and assess the associations between the extent of residential building damage and adverse perinatal outcomes and access to prenatal care (PNC) services.  METHODS: Vital statistics data from the Florida Department of Health's Office of Vital Statistics were used to align maternal geocoded address data to high-resolution imagery (0.5-foot resolution, true color with red, blue, and green bands) aerial photographs. Machine learning (support vector machines) classified residential roof damage across the study area. Perinatal outcomes were compared with the presence or absence of damage to the mother's home. Log-binomial regression models were used to compare the populations living in and outside of high-risk/damage areas, to assess the population changes after Hurricane Michael, and to estimate the associations between damage after Hurricane Michael and adverse perinatal outcomes/access to PNC services. A semi-parametric linear model was used to model time of first PNC visit and increase in damage.

RESULTS

We included 8,965 women in analysis. Women with lower education and/or of Black or other non-White race/ethnicity were more likely to live in areas that would see high damage than other groups. Moreover, there was a greater proportion of births delivered by women living in the high-risk/damage area (> 25% damaged parcels after Michael) in the year before Michael than the year after Michael. Lastly, living in the area with relatively high damage increased the risk of having intermediate or inadequate PNC (adjusted Risk Ratio = 1.21, 95% CI: 1.03, 1.43), but not other adverse perinatal outcomes.

CONCLUSIONS

Aerially observed damage data enable us to evaluate the impact of natural disasters on perinatal outcomes and access to PNC services based on residential building damage immediately surrounding a household. The association between the extent of damage and adverse perinatal outcomes should be further investigated in future studies.

Vicarious structural racism and infant health disparities in Michigan: The Flint Water Crisis

Building on nascent literature examining the health-related effects of vicarious structural racism, we examined indirect exposure to the Flint Water Crisis (FWC) as a predictor of birth outcomes in Michigan communities outside of Flint, where residents were not directly exposed to lead-contaminated water. Using linear regression models, we analyzed records for all singleton live births in Michigan from 2013 to 2016, excluding Flint, to determine whether birth weight (BW), gestational age (GA), and size-for-gestational-age (SzGA) decreased among babies born to Black people, but not among babies born to White people, following the highly publicized January 2016 emergency declaration in Flint. In adjusted regression models, BW and SzGA were lower for babies born to both Black and White people in the 37 weeks following the emergency declaration compared to the same 37-week periods in the previous 3 years. There were no racial differences in the association of exposure to the emergency declaration with BW or SzGA. Among infants born to Black people, GA was 0.05 weeks lower in the 37-week period following the emergency declaration versus the same 37-week periods in the previous 3 years (95% CI: -0.09, -0.01; p = 0.0177), while there was no change in GA for infants born to White people following the emergency declaration (95% CI: -0.01, 0.03; p = 0.6962). The FWC, which was widely attributed to structural racism, appears to have had a greater impact, overall, on outcomes for babies born to Black people. However, given the frequency of highly publicized examples of anti-Black racism over the study period, it is difficult to disentangle the effects of the FWC from the effects of other racialized stressors.

Hurricane Michael and Adverse Birth Outcomes in the Florida Panhandle: Analysis of Vital Statistics Data

OBJECTIVE

The aim of this study was to examine birth outcomes in areas affected by Hurricane Michael.

METHODS

Vital statistics data of 2017-2019 were obtained from the state of Florida. Births occurring in the year before and after the date of Hurricane Michael (October 7, 2018) were used. Florida counties were divided into 3 categories reflecting extent of impact from Hurricane Michael. Birth outcomes including incidence of preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA) were also compared before and after Hurricane Michael. Spontaneous and indicated PTBs were distinguished based on previously published algorithms. Multiple regression was used to control for potential confounders.

RESULTS

Both LBW (aRR 1.19, 95% CI: 1.07, 1.32) and SGA (aRR 1.11, 95% CI: 1.01, 1.21) were higher in the year after Michael than the year before in the most-affected area; a similar effect was not seen in other areas. A stronger effect was seen for exposure in the first trimester or in the 2 months after Michael than in the second or third trimester.

CONCLUSION

Consistent with many previous studies, this study of Hurricane Michael found an effect on fetal growth.

Louisiana Medicaid Expansion Associated With Reduced Travel For Care Among Minority Groups And Rural Residents

Distance traveled to a provider has been associated with access to and timely use of health care services. Medicaid expansion has been previously linked to an increase in the number of providers accepting Medicaid patients. We hypothesized that by increasing the density of providers accepting Medicaid in any area, Louisiana's Medicaid expansion in July 2016 may have increased access to health care services for Medicaid patients already eligible for Medicaid in Louisiana by decreasing distances traveled to reach health care providers. We tested our hypothesis using a regression discontinuity model on all continuously enrolled Louisiana Medicaid beneficiaries' transactions from the period 2015-17 across eight different service lines. Distance traveled to appointments declined across all service lines, with declines ranging from -3.46 miles for general practices to -0.70 miles for specialty care. The most robust declines in distance traveled were among Black enrollees living in nonmetropolitan areas, with the largest being a decline of 9.25 fewer miles traveled for general practice care. Medicaid expansion has the potential to address racial and geographic disparities in health care access through decreased travel distances.

Effects of maternal exposure to acute stress on birth outcomes: a quasi-experiment study

Numerous studies have shown associations between maternal stress and poor birth outcomes, but evidence is unclear for causal inference. Natural disasters provide an opportunity to study effects of quasi-randomized hardship with an accurate measure of onset and duration. In a population-based quasi-experimental study, we examined the effect of maternal exposure to the January 1998 Québec ice storm on birth outcomes by comparing pregnant mothers who lived in an area hard hit by the ice storm with those in two unaffected regions. In a total of 147,349 singleton births between 1995 and 2001, we used a difference-in-differences method to estimate the effects of the ice storm on gestational age at delivery (GA), preterm birth (PTB), weight-for-gestational-age z-scores (BWZ), large for gestational age (LGA), and small for gestational age (SGA). After adjusting for maternal and sociodemographic characteristics, there were no differences between the exposed and the unexposed mothers for birth outcomes. The estimated differences (exposed vs. unexposed) were 0.01 SDs (95% CI: -0.02, 0.05) for BWZ; 0.10% point (95% CI: -0.95%, 1.16%) for SGA; 0.25% point (95% CI: -0.78%, 1.28%) for LGA; -0.01 week (95% CI: -0.07, 0.05) for GA; and 0.16% point (95% CI: -0.66%, 0.97%) for PTB. Neither trimester-specific nor dose-response associations were observed. Overall, exposure to the 1998 Québec ice storm as a proxy for acute maternal stress in pregnancy was not associated with poor birth outcomes. Our results suggest that acute maternal hardship may not have a substantial effect on adverse birth outcomes.

Assessing the effects of disasters and their aftermath on pregnancy and infant outcomes: A conceptual model

Although many studies have examined broad patterns of effects on pregnancy and infant outcomes after disasters, the causes of adverse outcomes are not always clear. Disasters cause interrelated exposure to environmental pollutants, psychological stressors, and lack of health care, and interacts with other social determinants of health. This topical review examines the short- and long-term effects of disasters on pregnancy and how they are mediated by social, behavioral, and environmental effects. In the short term, disasters are associated with physical trauma, adverse environmental exposures, and unstable housing. In the longer term, disasters may lead to relocation, changes in family functioning, and negative economic effects. These aspects of disaster exposure, in turn, lead to lack of access to health care, increased stress and negative mental health outcomes, and negative behavioral changes, including smoking and substance use, poor nutrition, physical overexertion and limited activity, and reduction in breastfeeding. All of these factors interact with social determinants of health to worsen effects on the most vulnerable women, infants, and communities. Few interventions after disasters have been tested. With the increase in disasters due to climate change and the ongoing coronavirus pandemic, the models of effects of disasters and their human health consequences need increasing refinement, and, more importantly, should be applied to interventions that improve disaster prevention, mitigation, and response.

Maternal and newborn health risks of climate change: A call for awareness and global action

Climate change represents one of the largest global health threats of the 21st century with immediate and long-term consequences for the most vulnerable populations, especially in the poorest countries with the least capacity to adapt to climate change. Pregnant women and newborns are increasingly being recognized as vulnerable populations in the context of climate change. The effects can be direct or indirect through heat stress, extreme weather events and air pollution, potentially impacting both the immediate and long-term health of pregnant women and newborns through a broad range of mechanisms. In 2008, the World Health Organization passed a resolution during the 61st World Health Assembly, recognizing the need for research to identify strategies and health-system strengthening to mitigate the effects of climate change on health. Climate adaptation plans need to consider vulnerable populations such as pregnant women and neonates and a broad multisectoral approach to improve overall resilience of societies.

Birth outcomes, pregnancy complications, and postpartum mental health after the 2013 Calgary flood: A difference in difference analysis

Background

In June 2013, the city of Calgary, Alberta and surrounding areas sustained significant flooding which resulted in large scale evacuations and closure of businesses and schools. Floods can increase stress which may negatively impact perinatal outcomes and mental health, but previous research is inconsistent. The objectives of this study are to examine the impact of the flood on pregnancy health, birth outcomes and postpartum mental health.

Methods

Linked administrative data from the province of Alberta were used. Outcomes included preterm birth, small for gestational age, a new diagnoses of preeclampsia or gestational hypertension, and a diagnosis of, or drug prescription for, depression or anxiety. Data were analyzed using a quasi-experimental difference in difference design, comparing flooded and non-flooded areas and in affected and unaffected time periods. Multivariable log binomial regression models were used to estimate risk ratios, adjusted for maternal age. Marginal probabilities for the difference in difference term were used to show the potential effect of the flood.

Results

Participants included 18,266 nulliparous women for the pregnancy outcomes, and 26,956 women with infants for the mental health analysis. There were no effects for preterm birth (DID 0.00, CI: -0.02, 0.02), small for gestational age (DID 0.00, CI: -0.02, 0.02), or new cases of preeclampsia (DID 0.00, CI: -0.01, 0.01). There was a small increase in new cases of gestational hypertension (DID 0.02, CI: 0.01, 0.03) in flood affected areas. There were no differences in postpartum anxiety or depression prescriptions or diagnoses.

Conclusion

The Calgary 2013 flood was associated with a minor increase in gestational hypertension and not other health outcomes. Universal prenatal care and magnitude of the disaster may have minimized impacts of the flood on pregnant women.

Effects of Hurricane Michael on Access to Care for Pregnant Women and Associated Pregnancy Outcomes

Background: Disasters are associated with worse perinatal outcomes, perhaps due to inadequate prenatal care (PNC). Methods: Using 2017-2019 Florida vital statistics, we compared PNC use before and after Hurricane Michael. We categorized counties as most affected (Area A) or less affected (Area B and C). We examined whether Michael's effects on perinatal outcomes varied by maternity care availability and used the Baron and Kenny method to assess whether delayed PNC initiation mediated perinatal outcomes. Log-binomial regression and semi-parametric linear regression were used, controlling for maternal and ZIP code tabulation area characteristics. Results: Compared to the one-year period pre-Michael, the week of the first PNC was later in all areas in the one-year period post-Michael, with the largest change in Area A (adjusted difference 0.112, 95% CI: 0.055-0.169), where women were less likely to receive PNC overall (aRR = 0.994, 95% CI = 0.990-0.998) and more likely to have inadequate PNC (aRR = 1.193, 95% CI = 1.127-1.264). Michael's effects on perinatal outcomes did not vary significantly by maternity care availability within Area A. Delayed PNC initiation appeared to mediate an increased risk in small for gestational age (SGA) births after Michael. Conclusion: Women in Area A initiated PNC later and had a higher likelihood of inadequate PNC. Delayed PNC initiation may partially explain increased risk of SGA.

Maternal exposure to Wenchuan earthquake and prolonged risk of offspring birth outcomes: a natural experiment study

Background

The prolonged effects of disasters on reproductive outcomes among the survivors are less studied, and the findings are inconsistent. We examined the associations of maternal exposure to the 2008 Wenchuan earthquake years before conception with adverse birth outcomes.

Methods

We included 73,493 women who delivered in 96 hospitals in 24 provinces and autonomous regions from the 2015/16 China Labor and Delivery Survey. We weighted the multivariable logistic models based on the combination of coarsened exact matching (CEM) weight and survey weight, and performed sex-stratified analysis to test whether associations of maternal earthquake exposure with adverse birth outcomes (Stillbirth, preterm birth [PTB], low birthweight [LBW], and small for gestational age [SGA]) varied by sex.

Results

The bivariate models showed that the weighted incidence of each adverse birth outcome was higher in exposed group than unexposed group: stillbirth (2.00% vs. 1.33%), PTB (14.14% vs. 7.32%), LBW (10.82% vs. 5.76%), and SGA (11.32% vs. 9.52%). The multivariable models showed maternal earthquake exposure was only associated significantly with a higher risk of PTB in offspring among all births (adjusted risk ratio [aRR](95%CI):1.25(1.06–1.48), P = 0.010). The sex-stratified analysis showed the association was significant among male births (aRR (95%CI): 1.40(1.12–1.75),P = 0.002),but unsignificant among female births. The sensitivity analysis reported similar findings.

Conclusions

The 2008 Wenchuan earthquake exposure has a long-term effect on PTB. Maternal acute exposure to disasters could be a major monitor for long-term reproductive outcomes. More attention should be paid to the underlining reasons for disaster-related adverse birth outcomes.

The Paradoxical Effects of Hurricane Katrina on Births and Adverse Birth Outcomes

Objectives. To review the trends in pregnancy outcomes after Hurricane Katrina and assess effects of the disaster on research and public health related to pregnant women.Methods. We reexamined the 2004-2006 vital statistics data from Alabama, Louisiana, and Mississippi, assessing what the risk of adverse pregnancy outcomes in the population would have been under varying risk scenarios.Results. We saw a reduction in number of births as well as in low birth weight and preterm birth. If the number of births had stayed constant and the relative higher risk in the "missing" births had been between 17% and 100%, the storm would have been associated with an increased risk instead of a decrease. Because the relative decline in births was larger in Black women, the higher risk in the "missing" births required to create a significant increase associated with the storm was generally not as great as for White women.Conclusions. Higher exposure to Katrina may have produced a reduction in births among high-risk women in the region rather than increasing adverse outcomes among those who did give birth.

Tropical cyclones and risk of preterm birth: A retrospective analysis of 20 million births across 378 US counties

BACKGROUND

The public health impacts of tropical cyclones (TCs) are expected to increase due to the continued growth of coastal populations and the increasing severity of these events. However, the impact of TCs on pregnant women, a vulnerable population, remains largely unknown. We aimed to estimate the association between prenatal exposure to TCs and risk of preterm birth in the eastern United States (US) and to assess whether the association varies by individual- and area-level characteristics.

METHODS

We included data on 19,529,748 spontaneous singleton births from 1989 to 2002 across 378 US counties. In each county, we classified days as exposed to a TC when TC-associated peak sustained winds at the county's population-weighted center were >17.2 m/s (gale-force winds or greater). We defined preterm birth as births delivered prior to 37 completed weeks of gestation. We used distributed lag log-linear mixed-effects models to estimate the relative risk (RR) and absolute risk difference (ARD) for TC exposure by comparing preterm births occurring in TC-periods (from 2 days before to 30 days after the TC's closest approach to the county's population center) to matched non-TC periods. We conducted secondary analyses using other wind thresholds (12 m/s and 22 m/s) and other exposure metrics: county distance to storm track (30 km, 60 km, and 100 km) and cumulative rainfall within the county (75 mm, 100 mm, and 125 mm).

RESULTS

During the study period, there were 1,981,797 (10.1%) preterm births and 58 TCs that affected at least one US county on which we had birth data. The risk of preterm birth was positively associated with TC exposure defined as peak sustained wind speed >17.2 m/s (gale-force winds or greater) [RR: 1.01 (95% CI: 0.99, 1.03); ARD: 9 (95% CI: -7, 25) per 10,000 pregnancies], distance to storm track <60 km [RR: 1.02 (95% CI: 1.01, 1.04); ARD: 23 (95% CI: 9, 38) per 10,000 pregnancies], and cumulative rainfall >100 mm [RR: 1.04 (95% CI: 1.02, 1.06); ARD: 36 (95% CI: 16, 56) per 10,000 pregnancies]. Results were comparable when considering other wind, distance, or rain thresholds. The association was more pronounced among early preterm births and mothers living in more socially vulnerable counties but did not vary across strata of other hypothesized risk factors.

CONCLUSIONS

Maternal exposure to TC was associated with a higher risk of preterm birth. Our findings provide initial evidence that severe storms may trigger preterm birth.

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

OBJECTIVE

To appraise and analyze published research on the relationships among hurricane exposure and adverse pregnancy and birth outcomes.

DATA SOURCES

A literature search was conducted in four electronic databases: CINAHL Plus, Embase, PubMed, and Web of Science. The following search terms were used: "cyclonic storms," "cesarean section," "premature birth," "fetal mortality," "low birth weight," "infant mortality," "pregnancy complications," and "pregnancy outcome."

STUDY SELECTION

Documents were included if they were peer-reviewed, full-text articles or government documents published in English through February 2020 that focused on the associations among exposure to hurricanes and adverse pregnancy and birth outcomes. The initial search yielded 211 articles, and one article was identified through a hand search. After 48 duplicates were removed, we screened the titles and abstracts of 164 articles. We conducted a full-text review of 57 articles, and 19 articles were included in the integrative review.

DATA EXTRACTION

We extracted data from the full text of each article into a standardized table with the following headings: author, year of publication, location, hurricane and year, population studied, study design, outcomes, data source, and results.

DATA SYNTHESIS

We analyzed study findings based on the outcomes of pregnancy complications, preterm birth, cesarean birth, labor and birth complications, low birth weight, abnormal newborn conditions, and fetal mortality. We synthesized data in a narrative format, and the synthesis indicated that hurricane exposure was frequently associated with pregnancy complications, preterm birth, low birth weight, cesarean birth, and abnormal newborn conditions. However, these associations were not always consistent. Extant research is limited by inconsistency among study designs and the type of hurricane exposure.

CONCLUSION

Interdisciplinary teams that include nurses, midwives, obstetricians and gynecologists, and other health care professionals should ensure that hurricane preparedness and response efforts specifically address the needs of pregnant women to mitigate adverse outcomes.

Potential Climate Change Health Risks from Increases in Heat Waves: Abnormal Birth Outcomes and Adverse Maternal Health Conditions

We investigate the risks presented by heat waves for adverse health conditions for babies and expectant mothers when these mothers have been exposed to heat waves during gestation or during the period just prior to conception. Rather than just birth weight and gestational age, we focus on less common metrics such as abnormal conditions in the newborn (fetal distress, reliance on a ventilator, and meconium aspiration) and adverse health conditions in the mother (pregnancy-related hypertension, uterine bleeding during pregnancy, eclampsia, and incompetent cervix). We use monthly panel data for over 3,000 U.S. counties, constructed from the confidential version of the U.S. Natality Files for 1989-2008. Our models control for sociodemographic factors and include county, month, and state-by-year fixed effects to control for unobserved spatial and timewise heterogeneity in the data. Even within the United States, where there is widespread access to air conditioning, heat waves increase the fraction of babies with abnormal conditions related to maternal stress, as well as the fraction of mothers who experience pregnancy-related adverse health conditions. The scope for these risks in developing countries is likely to be even greater.

Birth Outcomes after the Fukushima Daiichi Nuclear Power Plant Disaster: A Long-Term Retrospective Study

Changes in population birth outcomes, including increases in low birthweight or preterm births, have been documented after natural and manmade disasters. However, information is limited following the 2011 Fukushima Daiichi Nuclear Power Plant Disaster. In this study, we assessed whether there were long-term changes in birth outcomes post-disaster, compared to pre-disaster data, and whether residential area and food purchasing patterns, as proxy measurements of evacuation and radiation-related anxiety, were associated with post-disaster birth outcomes. Maternal and perinatal data were retrospectively collected for all live singleton births at a public hospital, located 23 km from the power plant, from 2008 to 2015. Proportions of low birthweight (<2500 g at birth) and preterm births (<37 weeks gestation at birth) were compared pre- and post-disaster, and regression models were conducted to assess for associations between these outcomes and evacuation and food avoidance. A total of 1101 live singleton births were included. There were no increased proportions of low birthweight or preterm births in any year after the disaster (merged post-disaster risk ratio of low birthweight birth: 0.98, 95% confidence interval (CI): 0.64–1.51; and preterm birth: 0.68, 95% CI: 0.38–1.21). No significant associations between birth outcomes and residential area or food purchasing patterns were identified, after adjustment for covariates. In conclusion, no changes in birth outcomes were found in this institution-based investigation after the Fukushima disaster. Further research is needed on the pathways that may exacerbate or reduce disaster effects on maternal and perinatal health.

Impact of Hurricane Exposure on Reproductive Health Outcomes, Florida, 2004

OBJECTIVE

Prenatal hurricane exposure may be an increasingly important contributor to poor reproductive health outcomes. In the current literature, mixed associations have been suggested between hurricane exposure and reproductive health outcomes. This may be due, in part, to residual confounding. We assessed the association between hurricane exposure and reproductive health outcomes by using a difference-in-difference analysis technique to control for confounding in a cohort of Florida pregnancies.

METHODS

We implemented a difference-in-difference analysis to evaluate hurricane weather and reproductive health outcomes including low birth weight, fetal death, and birth rate. The study population for analysis included all Florida pregnancies conceived before or during the 2003 and 2004 hurricane season. Reproductive health data were extracted from vital statistics records from the Florida Department of Health. In 2004, 4 hurricanes (Charley, Frances, Ivan, and Jeanne) made landfall in rapid succession; whereas in 2003, no hurricanes made landfall in Florida.

RESULTS

Overall models using the difference-in-difference analysis showed no association between exposure to hurricane weather and reproductive health.

CONCLUSIONS

The inconsistency of the literature on hurricane exposure and reproductive health may be in part due to biases inherent in pre-post or regression-based county-level comparisons. We found no associations between hurricane exposure and reproductive health. (Disaster Med Public Health Preparedness. 2017;11:407-411).

Birth Outcomes in a Disaster Recovery Environment: New Orleans Women After Katrina

OBJECTIVES

To examine how the recovery following Hurricane Katrina affected pregnancy outcomes.

METHODS

308 New Orleans area pregnant women were interviewed 5-7 years after Hurricane Katrina about their exposure to the disaster (danger, damage, and injury); current disruption; and perceptions of recovery. Birthweight, gestational age, birth length, and head circumference were examined in linear models, and low birthweight (<2500 g) and preterm birth (<37 weeks) in logistic models, with adjustment for confounders.

RESULTS

Associations were found between experiencing damage during Katrina and birthweight (adjusted beta for high exposure = -158 g) and between injury and gestational age (adjusted beta = -0.5 days). Of the indicators of recovery experience, most consistently associated with worsened birth outcomes was worry that another hurricane would hit the region (adjusted beta for birthweight: -112 g, p = 0.08; gestational age: -3.2 days, p = 0.02; birth length: -0.65 cm, p = 0.06).

CONCLUSIONS

Natural disaster may have long-term effects on pregnancy outcomes. Alternately, women who are most vulnerable to disaster may be also vulnerable to poor pregnancy outcome.

County-level hurricane exposure and birth rates: application of difference-in-differences analysis for confounding control

Background

Epidemiological analyses of aggregated data are often used to evaluate theoretical health effects of natural disasters. Such analyses are susceptible to confounding by unmeasured differences between the exposed and unexposed populations. To demonstrate the difference-in-difference method our population included all recorded Florida live births that reached 20 weeks gestation and conceived after the first hurricane of 2004 or in 2003 (when no hurricanes made landfall). Hurricane exposure was categorized using ≥74 mile per hour hurricane wind speed as well as a 60 km spatial buffer based on weather data from the National Oceanic and Atmospheric Administration. The effect of exposure was quantified as live birth rate differences and 95 % confidence intervals [RD (95 % CI)]. To illustrate sensitivity of the results, the difference-in-differences estimates were compared to general linear models adjusted for census-level covariates. This analysis demonstrates difference-in-differences as a method to control for time-invariant confounders investigating hurricane exposure on live birth rates.

Results

Difference-in-differences analysis yielded consistently null associations across exposure metrics and hurricanes for the post hurricane rate difference between exposed and unexposed areas (e.g., Hurricane Ivan for 60 km spatial buffer [−0.02 births/1000 individuals (−0.51, 0.47)]. In contrast, general linear models suggested a positive association between hurricane exposure and birth rate [Hurricane Ivan for 60 km spatial buffer (2.80 births/1000 individuals (1.94, 3.67)] but not all models.

Conclusions

Ecological studies of associations between environmental exposures and health are susceptible to confounding due to unmeasured population attributes. Here we demonstrate an accessible method of control for time-invariant confounders for future research.

Electronic supplementary material

The online version of this article (doi:10.1186/s12982-015-0042-7) contains supplementary material, which is available to authorized users.

When is exposure to a natural disaster traumatic? Comparison of a trauma questionnaire and disaster exposure inventory

Few studies have compared the sensitivity of trauma questionnaires to disaster inventories for assessing the prevalence of exposure to natural disaster or associated risk for post-disaster psychopathology. The objective of this analysis was to compare reporting of disaster exposure on a trauma questionnaire (Brief Trauma Questionnaire [BTQ]) to an inventory of disaster experience. Between 2011 and 2014, a sample of 841 reproductive-aged southern Louisiana women were interviewed using the BTQ and completed a detailed inventory about exposure to hurricanes and flooding. Post-traumatic stress disorder (PTSD) symptomology was measured with the Post-Traumatic Stress Checklist, and depression with the Edinburgh Depression Scale. The single question addressing disaster exposure on the BTQ had a sensitivity of between 65% and 70% relative to the more detailed questions. Reporting disaster exposure on the BTQ was more likely for those who reported illness/injury due to a hurricane or flood (74%-77%) or danger (77-79%), compared to those who reported damage (69-71%) or evacuation (64-68%). Reporting disaster exposure on the BTQ was associated with depression (odds ratio [OR] 2.29, 95% confidence interval [CI] 1.43-3.68). A single question is unlikely to be useful for assessing the degree of exposure to disaster across a broad population, and varies in utility depending on the mental health outcome of interest: the single trauma question is useful for assessing depression risk.

Relationships among stress coping styles and pregnancy complications among women exposed to Hurricane Katrina

OBJECTIVE

To examine the relationship between maternal stress exposure, stress coping styles, and pregnancy complications.

DESIGN

Quantitative, cross-sectional, and prospective study.

SETTING

Tulane-Lakeside Hospital, New Orleans, LA and Women's Hospital, Baton Rouge, LA.

PARTICIPANTS

The study included 146 women (122 from New Orleans and 24 from Baton Rouge), who were pregnant during or immediately after Hurricane Katrina.

METHODS

Participants were interviewed regarding their hurricane experiences and perceived stress, and coping styles were assessed using the Brief COPE. Medical charts were also reviewed to obtain information about pregnancy outcomes. Logistic regression was performed to determine possible associations.

RESULTS

Hurricane exposure was significantly associated with induction of labor (adjusted odds ratio [aOR] = 1.39; 95% confidence interval [CI] [1.03, 1.86], P = .03) and current perceived stress (aOR = 1.50, CI [1.34, 1.99], P < .01). Stress perception significantly predisposed to pregnancy-induced hypertension (aOR = 1.16, CI [1.05, 1.30], P < .01) and gestational diabetes (aOR = 1.13, CI [1.02, 1.25], P = .03). Use of planning, acceptance, humor, instrumental support, and venting coping styles were associated with a significantly reduced occurrence of pregnancy complications (P < .05). Higher rates for gestational diabetes was found among women using the denial coping style (aOR = 2.25, CI [1.14, 4.45], P = .02).

CONCLUSION

Exposure to disaster-related stress may complicate pregnancy, whereas some coping styles may mitigate its effects. Further research should explore how coping styles may mitigate or exacerbate the effect of major stressors and how positive coping styles can be encouraged or augmented.

Post-disaster reproductive health outcomes

We examined methodological issues in studies of disaster-related effects on reproductive health outcomes and fertility among women of reproductive age and infants in the United States (US). We conducted a systematic literature review of 1,635 articles and reports published in peer-reviewed journals or by the government from January 1981 through December 2010. We classified the studies using three exposure types: (1) physical exposure to toxicants; (2) psychological trauma; and (3) general exposure to disaster. Fifteen articles met our inclusion criteria concerning research focus and design. Overall studies pertained to eight different disasters, with most (n = 6) focused on the World Trade Center attack. Only one study examined pregnancy loss, i.e., occurrence of spontaneous abortions post-disaster. Most studies focused on associations between disaster and adverse birth outcomes, but two studies pertained only to post-disaster fertility while another two examined it in addition to adverse birth outcomes. In most studies disaster-affected populations were assumed to have experienced psychological trauma, but exposure to trauma was measured in only four studies. Furthermore, effects of both physical exposure to toxicants and psychological trauma on disaster-affected populations were examined in only one study. Effects on birth outcomes were not consistently demonstrated, and study methodologies varied widely. Even so, these studies suggest an association between disasters and reproductive health and highlight the need for further studies to clarify associations. We postulate that post-disaster surveillance among pregnant women could improve our understanding of effects of disaster on the reproductive health of US pregnant women.

Prevalence of insomnia among residents of Tokyo and osaka after the great East Japan earthquake: a prospective study

Background

The Great East Japan Earthquake occurred on March 11, 2011. Tokyo and Osaka, which are located 375 km and 750 km, respectively, from the epicenter, experienced tremors of 5.0 lower and 3.0 seismic intensity on the Japan Meteorological Agency scale. The Great East Japan Earthquake was the fourth largest earthquake in the world and was accompanied by a radioactive leak at a nuclear power plant and a tsunami. In the aftermath of a disaster, some affected individuals presented to mental health facilities with acute stress disorder (ASD) and/or post-traumatic stress disorder (PTSD). However, few studies have addressed mental stress problems other than ASD or PTSD among the general public immediately after a disaster. Further, the effects of such a disaster on residents living at considerable distances from the most severely affected area have not been examined.

Objective

This study aimed to prospectively analyze the effect of a major earthquake on the prevalence of insomnia among residents of Tokyo and Osaka.

Methods

A prospective online questionnaire study was conducted in Tokyo and Osaka from January 20 to April 30, 2011. An Internet-based questionnaire, intended to be completed daily for a period of 101 days, was used to collect the data. All of the study participants lived in Tokyo or Osaka and were Consumers’ Co-operative Union (CO-OP) members who used an Internet-based food-ordering system. The presence or absence of insomnia was determined before and after the earthquake. These data were compared after stratification for the region and participants’ age. Multivariate analyses were conducted using logistic regression and a generalized estimating equation. This study was conducted with the assistance of the Japanese CO-OP.

Results

The prevalence of insomnia among adults and minors in Tokyo and adults in Osaka increased significantly after the earthquake. No such increase was observed among minors in Osaka. The overall adjusted odds ratios for the risk of insomnia post-earthquake versus pre-earthquake were 1.998 (95% CI 1.571–2.542) for Tokyo, 1.558 (95% CI 1.106–2.196) for Osaka, and 1.842 (95% CI,1.514–2.242) for both areas combined.

Conclusions

The prevalence of insomnia increased even in regions that were at a considerable distance from the epicenter. Both adults and minors in Tokyo, where the seismic intensity was greater, experienced stress after the earthquake. In Osaka, where the earthquake impact was milder, disturbing video images may have exacerbated insomnia among adults.

Reproductive Health Assessment After Disaster: introduction to the RHAD toolkit

This article reviews associations between disaster and the reproductive health of women, describes how Hurricane Katrina influenced our understanding about postdisaster reproductive health needs, and introduces a new toolkit that can help health departments assess postdisaster health needs among women of reproductive age.