The impact of altitude on infant health in South America

Altitude and Its Association with Low Birth Weight among Children of 151,873 Peruvian Women: A Pooled Analysis of a Nationally Representative Survey

The aim of this study was to determine the relationship between the altitude of residence and the low birth weight (LBW) of the children of pregnant Peruvian women using a nationally representative database. An analysis of individual-level data from the last 13 years (from 2009 to 2021) of the Demographic and Family Health Survey was performed. The outcome variable was LBW, defined as birth weight less than 2500 g, while the independent variable was the altitude of residence in meters above sea level (masl). To estimate the association between the two variables, the crude and adjusted generalized linear model of the Poisson family with a log link was used along with crude and adjusted prevalence ratios, which were estimated with their respective 95% confidence interval. A total of 151,873 women aged 15-49 years were included between 2009 and 2021. The pooled proportion of LBW was 7.0%. As the main finding, the children of mothers residing at an altitude from 2500 to 3499 masl and ≥3500 masl had a higher probability of LBW. It was found that the children of mothers residing at an altitude above 2500 masl were more likely to have LBW. Our results will help to strengthen the cultural practice of maternal health care and increase its coverage in women residing in high-altitude regions.

Are High-Altitude Residents More Susceptible to Covid-19 in India? Findings and Potential Implications for Research and Policy

In this paper, we study the incidence of COVID-19 and the associated fatality with altitude using high frequency, district level data from India. To understand the implications of the nationwide lockdown after the outbreak, we use data for about four months- two from the lockdown period starting from March 25 till May 31, 2020 and about two months after unlocking was initiated (June 1-July 26, 2020). The multivariate regression result indicates slower growth in average rate of infection during the lockdown period in hilly regions, the gains of which attenuated after the unlocking was initiated. Despite these early gains, the rate of fatalities is significantly higher during the lockdown period in comparison to the plains. The findings remain robust to multiple alternative specifications and methods including one that accounts for confounding possibilities via unobservable and provides consistent estimates of bias adjusted treatment effects. The evidence supports the need for provisioning of public health services and infrastructure upgradation, especially maintenance of adequate stock of life support devices, in high altitude regions. It also underscores the necessity for strengthening and revising the existing Hill Areas Development Programme and integrating important aspects of public health as part of this policy.

Near-Infrared Spectroscopy Monitoring of Cerebral Oxygenation and Influencing Factors in Neonates from High-Altitude Areas

BACKGROUND

Accurate detection of cerebral oxygen saturation (rSO2) may be useful for neonatal brain injury prevention, and the normal range of rSO2 of neonates at high altitude remained unclear.

OBJECTIVE

To compare cerebral rSO2 and cerebral fractional tissue oxygen extraction (cFTOE) at high-altitude and low-altitude areas in healthy neonates and neonates with underlying diseases.

METHODS

515 neonates from low-altitude areas and 151 from Tibet were enrolled. These neonates were assigned into the normal group, hypoxic-ischemic encephalopathy (HIE) group, and other diseases group. Near-infrared spectroscopy was used to measure rSO2 in neonates within 24 h after admission. The differences of rSO2, pulse oxygen saturation (SpO2), and cFTOE levels were compared between neonates from low- and high-altitude areas.

RESULTS

(1) The mean rSO2 and cFTOE levels in normal neonates from Tibet were 55.0 ± 6.4% and 32.6 ± 8.5%, significantly lower than those from low-altitude areas (p < 0.05). (2) At high altitude, neonates with HIE, pneumonia (p < 0.05), anemia, and congenital heart disease (p < 0.05) have higher cFTOE than healthy neonates. (3) Compared with HIE neonates from plain areas, neonates with HIE at higher altitude had lower cFTOE (p < 0.05), while neonates with heart disease in plateau areas had higher cFTOE than those in plain areas (p < 0.05).

CONCLUSIONS

The rSO2 and cFTOE levels in normal neonates from high-altitude areas are lower than neonates from the low-altitude areas. Lower cFTOE is possibly because of an increase in blood flow to the brain, and this may be adversely affected by disease states which may increase the risk of brain injury.

Maternal exposure to low-to-medium altitude and birth outcomes: evidence from a population-based study in Chinese newborns

Despite high altitude was implicated in adverse birth outcomes, there remained a paucity of evidence on low-to-medium altitude effect. This study aimed to explore the association of low-to-medium altitude with birth outcomes. A population-based cross-sectional survey was performed using a stratified multistage random sampling method among women with their infants born during 2010-2013 in Northwestern China. Altitude was determined in meters based on the village or community of the mother's living areas. Birth outcomes involved birth weight, gestational age, and small for gestational age (SGA). Generalized linear models were fitted to investigate the association of altitude with birth outcomes. Moreover, the dose-response relationship between altitude and birth outcomes was evaluated with a restricted cubic spline function. A total of 27 801 women with their infants were included. After adjusting for potential confounders, every 100-m increase in the altitude was associated with reduced birth weight by 6.4 (95% CI -8.1, -4.6) g, the slight increase of gestational age by 0.015 (95% CI 0.010, 0.020) week, and an increased risk of SGA birth (odds ratio 1.03, 95% CI 1.02, 1.04). Moreover, there was an inversely linear relationship between altitude and birth weight (P for overall < 0.001 and P for nonlinear = 0.312), and a positive linear relationship between altitude and SGA (P for overall < 0.001 and P for nonlinear = 0.194). However, a nonlinear relationship was observed between altitude and gestational age (P for overall < 0.001 and P for nonlinear = 0.010). The present results suggest that low-to-medium altitude is possibly associated with adverse birth outcomes.

The biological standard of living in La Paz (Bolivia), 1880s-1920s: Persistent stagnation and inequality

Based on almost 5.000 direct observations on National Identification Cards, this paper offers the first estimation of the evolution of average heights in the city of La Paz (Bolivia) for the decades 1880s-1920s. The analysis focuses on men of middle and upper classes aged 19-50 years old. Despite the city's growing economic importance and modernization, average heights remained stagnant around 163 cm. It also stands out that whereas average height differences between professional and ethnic groups remained significant and persistent throughout time, average heights remained stagnant in all groups. Three main reasons are provided to explain these inequalities between groups and stagnation across groups: scarce improvements in agricultural production, increasing wage inequalities and the persistence of a bad disease environment.

Moderate altitude impacts birth weight: 30 years retrospective sibling analyses using record linkage data

OBJECTIVE

We investigated the effect of a change of altitude of maternal living address on infant birth weight.

METHOD

Data on infant birth weights of the first and second pregnancies from same women were extracted from all Austrian birth certificates between 1984 and 2016.

RESULTS

A total of 544,624 pair pregnancies were identified and analyzed. We observed a statistically significant interaction (p < .0001) between altitudes of two births and birth weight. Among women having first birth at low altitude (200 m), the estimated second mean birth weight was 3567 g for those remained at low altitudes, and reduced to 3536 g for those ascended (1200 m). In contrast, among women having first births at high altitudes, the estimated birth weight of second birth at high altitude was 3414 g, yet increased to 3499 g compared to those descended to lower altitudes.

CONCLUSION

We demonstrated a longitudinal negative effect of altitude on birth weight within the same mother from first and second birth. This association is likely to be casual. Relocation of mothers within low-to-medium altitude level may have profound effects on infants' birth weight.

Multilevel analysis of individual, household, and community factors influencing child growth in Nepal

BACKGROUND

Childhood malnutrition and growth faltering is a serious concern in Nepal. Studies of child growth typically focus on child and mother characteristics as key factors, largely because Demographic and Health Surveys (DHS) collect data at these levels. To control for and measure the importance of higher-level factors this study supplements 2006 and 2011 DHS data for Nepal with data from coincident rounds of the Nepal Living Standards Surveys (NLSS). NLSS information is summarized at the district level and matched to children using district identifiers available in the DHS.

METHODS

The sample consists of 7533 children aged 0 to 59 months with complete anthropometric measurements from the 2006 and 2011 NDHS. These growth metrics, specifically height-for-age and weight-for-height, are used in multilevel regression models, with different group designations as upper-level denominations and different observed characteristics as upper-level predictors.

RESULTS

Characteristics of children and households explain most of the variance in height-for-age and weight-for-height, with statistically significant but relatively smaller overall contributions from community-level factors. Approximately 6% of total variance and 22% of explained variance in height-for-age z-scores occurs between districts. For weight-for-height, approximately 5% of total variance, and 35% of explained variance occurs between districts.

CONCLUSIONS

The most important district-level factors for explaining variance in linear growth and weight gain are the percentage of the population belonging to marginalized groups and the distance to the nearest hospital. Traditional determinants of child growth maintain their statistical power in the hierarchical models, underscoring their overall importance for policy attention.

The Role of Nutrition and Literacy on the Cognitive Functioning of Elderly Poor Individuals

Maintaining cognitive function is a prerequisite of living independently, which is a highly valued component in older individuals' well-being. In this article we assess the role of early-life and later-life nutritional status, education, and literacy on the cognitive functioning of older adults living in poverty in Peru. We exploit the baseline sample of the Peruvian noncontributory pension program Pension 65 and find that current nutritional status and literacy are strongly associated with cognitive functioning for poor older adults. In a context of rising popularity of noncontributory pension programs around the world, our study intends to contribute to the discussion of designing accompanying measures to the pension transfer, such as adult literacy programs and monitoring of adequate nutrition of older adults.

Maternal Education Gradients in Infant Health in Four South American Countries

Objective We investigate gradients (i.e. differences) in infant health outcomes by maternal education in Argentina, Brazil, Chile, and Venezuela and explore channels related to father's education, household labor outcomes, and maternal health, fertility, and use of prenatal services and technology. Methods We employ secondary interview and birth record data similarly collected across a network of birth hospitals from the early 1980s through 2011 within the Latin American Collaborative Study of Congenital Anomalies (ECLAMC). Focusing on children without birth defects, we estimate gradients in several infant health outcomes including birth weight, gestational age, and hospital discharge status by maternal education using ordinary least squares regression models adjusting for several demographic factors. To explore channels, we add as covariates father's education, parental occupational activity, maternal health and fertility history, and use of prenatal services and technology and evaluate changes in the coefficient of maternal education. We use the same models for each country sample. Results We find important differences in gradients across countries. We find evidence for educational gradients in preterm birth in three countries but weaker evidence for gradients in fetal growth. The extent to which observed household and maternal factors explain these gradients based on changes in the regression coefficient of maternal education when controlling for these factors as covariates also varies between countries. In contrast, we generally find evidence across all countries that higher maternal education is associated with increased use of prenatal care services and technology. Conclusions Our findings suggest that differences in infant health by maternal education and their underlying mechanisms vary and are not necessarily generalizable across countries. However, the positive association between maternal education and use of prenatal services and technology is more consistent across examined countries.

The Relationship between Socioeconomic Status, Family Income, and Measures of Muscular and Cardiorespiratory Fitness in Colombian Schoolchildren

OBJECTIVE

To determine the associations between socioeconomic status (SES) and physical fitness in a sample of Colombian youth.

STUDY DESIGN

Prueba SER is cross-sectional survey of schoolchildren in Bogota, Colombia. Mass, stature, muscular fitness (standing long-jump, handgrip), and cardiorespiratory fitness (20-m shuttle run) were measured in 52?187 schoolchildren 14-16 years of age. Area-level SES was categorized from 1 (very low) to 4 (high) and parent-reported family income was categorized as low, middle, or high.

RESULTS

Converting measures into z scores showed stature, muscular, and cardiorespiratory fitness were significantly (z?=?0.3-0.7) below European values. Children in the mid- and high SES groups jumped significantly further than groups with very low SES. Differences were independent of sex but became nonsignificant when adjusted for anthropometric differences. Participants in the mid-SES and high-SES groups had better handgrip scores when adjusted for body dimension. There were, however, no significant between-group differences in cardiorespiratory fitness, which was strongly clustered by school and significantly greater in students from private schools.

CONCLUSIONS

Area-level SES is associated with measures of muscular fitness in Colombian schoolchildren. These associations were largely explained by the large differences in body dimensions observed between SES groups. When area-level SES is considered, there was no evidence that family income influenced fitness. The clustering of outcomes reaffirms the potential importance of schools and area-level factors in promoting fitness through opportunities for physical activity. Interventions implemented in schools, can improve academic attainment; a factor likely to be important in promoting the social mobility of children from poorer families.

The perils of climate change: In utero exposure to temperature variability and birth outcomes in the Andean region

The discussion on the effects of climate change on human activity has primarily focused on how increasing temperature levels can impair human health. However, less attention has been paid to the effect of increased climate variability on health. We investigate how in utero exposure to temperature variability, measured as the fluctuations relative to the historical local temperature mean, affects birth outcomes in the Andean region. Our results suggest that exposure to a temperate one standard deviation relative to the municipality's long-term temperature mean during pregnancy reduces birth weight by 20g. and increases the probability a child is born with low birth weight by a 0.7 percentage point. We also explore potential channels driving our results and find some evidence that increased temperature variability can lead to a decrease in health care and increased food insecurity during pregnancy.

Differences in early cognitive and receptive-expressive neurodevelopment by ancestry and underlying pathways in Brazil and Argentina

We examine disparities in early child cognitive and receptive-expressive skills by ethnic ancestry among infants aged 3-24 months from Brazil and Argentina. We employ unique data on the neurodevelopment of children who were seeking routine well-child care at a set of pediatric clinics in these countries. The sample included children who had normal birth outcomes and no major health complications, allowing us to focus on variation in neurodevelopment among children without major physical health limitations. The physicians attending the pediatric clinics were trained in administering the Bayley Infant Neurodevelopmental Screener, a standardized instrument used to screen an infant's risk of neurodevelopmental problems on various domains of abilities. We evaluate disparities in overall neurodevelopmental scores and risk for neurodevelopmental problems as well as in cognitive functioning and receptive-expressive neurodevelopment. We also examine the extent to which household demographic and socioeconomic characteristics and geographic location explain these disparities. We find large gaps in both cognitive and receptive-expressive neurodevelopment by ancestry. In Brazil, children of African ancestry have lower scores on both cognitive and receptive-expressive domains and on overall neurodevelopment than children of European ancestry. In Argentina, children of Native ancestry have lower scores on these outcomes than children of European ancestry. These gaps however are largely explained by differences in geographic location and household characteristics, highlighting the importance of policies that reduce socioeconomic and geographic disparities in social capital and economic development for eliminating ethnic disparities in infant neurodevelopment.

Climatic conditions and child height: Sex-specific vulnerability and the protective effects of sanitation and food markets in Nepal

Environmental conditions in early life are known to have impacts on later health outcomes, but causal mechanisms and potential remedies have been difficult to discern. This paper uses the Nepal Demographic and Health Surveys of 2006 and 2011, combined with earlier NASA satellite observations of variation in the Normalized Difference Vegetation Index (NDVI) at each child's location and time of birth to identify the trimesters of gestation and periods of infancy when climate variation is linked to attained height later in life. We find significant differences by sex: males are most affected by conditions in their second trimester of gestation, and females in the first three months after birth. Each 100-point difference in NDVI at those times is associated with a difference in height-for-age z-score (HAZ) measured at age 12-59 months of 0.088 for boys and 0.054 for girls, an effect size similar to that of moving within the distribution of household wealth by close to one quintile for boys and one decile for girls. The entire seasonal change in NDVI from peak to trough is approximately 200-300 points during the 2000-2011 study period, implying a seasonal effect on HAZ similar to one to three quintiles of household wealth. This effect is observed only in households without toilets; in households with toilets, there is no seasonal fluctuation, implying protection against climatic conditions that facilitate disease transmission. We also use data from the Nepal Living Standards Surveys on district-level agricultural production and marketing, and find a climate effect on child growth only in districts where households' food consumption derives primarily from their own production. Robustness tests find no evidence of selection effects, and placebo regression results reveal no significant artefactual correlations. The timing and sex-specificity of climatic effects are consistent with previous studies, while the protective effects of household sanitation and food markets are novel indications of mechanisms by which households can gain resilience against adverse climatic conditions.

Explaining ethnic disparities in preterm birth in Argentina and Ecuador

Little is understood about racial/ethnic disparities in infant health in South America. We quantified the extent to which the disparity in preterm birth (PTB; <37 gestational weeks) rate between infants of Native only ancestry and those of European only ancestry in Argentina and Ecuador are explained by household socio-economic, demographic, healthcare use, and geographic location indicators. The samples included 5199 infants born between 2000 and 2011 from Argentina and 1579 infants born between 2001 and 2011 from Ecuador. An Oaxaca-Blinder type decomposition model adapted to binary outcomes was estimated to explain the disparity in PTB risk across groups of variables and specific variables. Maternal use of prenatal care services significantly explained the PTB disparity, by nearly 57% and 30% in Argentina and Ecuador, respectively. Household socio-economic status explained an additional 26% of the PTB disparity in Argentina. Differences in maternal use of prenatal care may partly explain ethnic disparities in PTB in Argentina and Ecuador. Improving access to prenatal care may reduce ethnic disparities in PTB risk in these countries.

Pregnancy at high altitude in the Andes leads to increased total vessel density in healthy newborns

The developing human fetus is able to cope with the physiological reduction in oxygen supply occurring in utero. However, it is not known if microvascularization of the fetus is augmented when pregnancy occurs at high altitude. Fifty-three healthy term newborns in Puno, Peru (3,840 m) were compared with sea-level controls. Pre- and postductal arterial oxygen saturation (SpO2) was determined. Cerebral and calf muscle regional tissue oxygenation was measured using near infrared spectroscopy (NIRS). Skin microcirculation was noninvasively measured using incident dark field imaging. Pre- and postductal SpO2 in Peruvian babies was 88.1 and 88.4%, respectively, which was 10.4 and 9.7% lower than in newborns at sea level (P < 0.001). Cerebral and regional oxygen saturation was significantly lower in the Peruvian newborns (cerebral: 71.0 vs. 74.9%; regional: 68.5 vs. 76.0%, P < 0.001). Transcutaneously measured total vessel density in the Peruvian newborns was 14% higher than that in the newborns born at sea level (29.7 vs. 26.0 mm/mm(2); P ≤ 0.001). This study demonstrates that microvascular vessel density in neonates born to mothers living at high altitude is higher than that in neonates born at sea level.

The impact of unemployment cycles on child and maternal health in Argentina

OBJECTIVES

The purpose of this study is to examine the effects of economic cycles in Argentina on infant and maternal health between 1994 and 2006, a period that spans the major economic crisis in 1999-2002.

METHODS

We evaluate the effects of province-level unemployment rates on several infant health outcomes, including birth weight, gestational age, fetal growth rate, and hospital discharge status after birth in a sample of 15,000 infants born in 13 provinces. Maternal health and healthcare outcomes include acute and chronic illnesses, infectious diseases, and use of prenatal visits and technology. Regression models control for hospital and year fixed effects and province-specific time trends.

RESULTS

Unemployment rise reduces fetal growth rate particularly among high educated parents. Also, maternal poverty-related infectious diseases increase, although reporting of acute illnesses declines (an effect more pronounced among low educated parents). There is also some evidence for reduced access to prenatal care and technology among less educated parents with higher unemployment.

CONCLUSIONS

Unemployment rise in Argentina has adversely affected certain infant and maternal health outcomes, but several measures show no evidence of significant change.

Explaining racial disparities in infant health in Brazil

OBJECTIVES

We sought to quantify how socioeconomic, health care, demographic, and geographic effects explain racial disparities in low birth weight (LBW) and preterm birth (PTB) rates in Brazil.

METHODS

We employed a sample of 8949 infants born between 1995 and 2009 in 15 cities and 7 provinces in Brazil. We focused on disparities in LBW (< 2500 g) and PTB (< 37 gestational weeks) prevalence between infants of African ancestry alone or African mixed with other ancestries, and European ancestry alone. We used a decomposition model to quantify the contributions of conceptually relevant factors to these disparities.

RESULTS

The model explained 45% to 94% of LBW and 64% to 94% of PTB disparities between the African ancestry groups and European ancestry. Differences in prenatal care use and geographic location were the most important contributors, followed by socioeconomic differences. The model explained the majority of the disparities for mixed African ancestry and part of the disparity for African ancestry alone.

CONCLUSIONS

Public policies to improve children's health should target prenatal care and geographic location differences to reduce health disparities between infants of African and European ancestries in Brazil.

The impact of altitude on birth weight depends on further mother- and infant-related factors: a population-based study in an altitude range up to 1600 m in Austria between 1984 and 2013

OBJECTIVE

A negative impact of altitude on birth weight has been demonstrated for medium to high-altitude countries.

STUDY DESIGN

The present study aims to show a similar effect for a lower altitude range up to 1600 m in the country of Austria and to adjust for several further risk factors related to mother and infant. In addition, we analyzed whether the effect of altitude influenced birth weight independently or interacted with other factors. For the purpose of this study, almost 1.9 million individual birth certificates of Austrian newborns born between 1984 and 2013 were analyzed. In a multivariate linear regression model, birth weight was associated with altitude of living address and following variables: sex, birth length, gestational age, level of education, maternal age, year of birth, parity, time to previous birth and marital status.

RESULT

Birth weight decreased by 150 g/1000 m altitude, demonstrating a clear effect of altitude on birth weight also in a low to medium altitude level. Additionally, we could show that this effect also depends on other factors, namely gestational age, education of the mother, sex, birth length, year of birth and time to previous delivery. All variables interacted significantly (p<0.0001) with altitude.

CONCLUSION

We observed a negative effect of altitude in an altitude range up to 1600 m. Furthermore, this effect also depends on other risk factors. Therefore, unadjusted estimates as described in many studies may be biased. This population-based study describes the effect of low-to-medium altitude on birth weight in central Europe over a period of 30 years.

Disparities in birth weight and gestational age by ethnic ancestry in South American countries

OBJECTIVES

We examine disparities in birth weight and gestational age by ethnic ancestry in 2000-2011 in eight South American countries.

METHODS

The sample included 60,480 singleton live births. Regression models were estimated to evaluate differences in birth outcomes by ethnic ancestry controlling for time trends.

RESULTS

Significant disparities were found in seven countries. In four countries-Brazil, Ecuador, Uruguay, and Venezuela-we found significant disparities in both low birth weight and preterm birth. Disparities in preterm birth alone were observed in Argentina, Bolivia, and Colombia. Several differences in continuous birth weight, gestational age, and fetal growth rate were also observed. There were no systematic patterns of disparities between the evaluated ethnic ancestry groups across the study countries, in that no racial/ethnic group consistently had the best or worst outcomes in all countries.

CONCLUSIONS

Racial/ethnic disparities in infant health are common in several South American countries. Differences across countries suggest that racial/ethnic disparities are driven by social and economic mechanisms. Researchers and policymakers should acknowledge these disparities and develop research and policy programs to effectively target them.

Evaluation of the thickness of the proximal femoral canal in patients living at altitude

OBJECTIVE:

Our goal is to confirm the hypothesis that people who were born and raised on cities at altitude have a smaller proximal femoral canal.

METHODS:

Prospective study with 169 participants, divided into two groups. Group A: 99 patients who were born and raised at altitude and group B: 70 patients who were born and raised at low altitude. All patients underwent panoramic radiographs of the pelvis, where we marked three measure and checked the thickness of the cortical and the lateral and medial cortical, as well as the thickness of the femoral canal.

RESULTS:

We noticed that the first measure showed no significant difference in both groups, but the second measure, the lateral cortex, is thicker in group A, and the femoral canal is smaller in comparison to group B.

CONCLUSION:

We concluded that patients who were born and raised at altitude have a smaller femoral canal. This may help in proper planning of future surgical procedures, especially in total hip arthroplasty cases.

Level of Evidence II, Development of Diagnostic Criteria in Consecutive Patients (with universally applied reference "gold" standard).

A comparative analysis of prenatal care and fetal growth in eight South American countries

There has been little work that comprehensively compared the relationship between prenatal care and infant health across multiple countries using similar data sources and analytical models. Such comparative analyses are useful for understanding the background of differences in infant health between populations. We evaluated the association between prenatal care visits and fetal growth measured by birth weight (BW) in grams or low birth weight (<2500 grams; LBW) adjusted for gestational age in eight South American countries using similarly collected data across countries and the same analytical models. OLS and logistic regressions were estimated adjusting for a large set of relevant infant, maternal, and household characteristics and birth year and hospital fixed effects. Birth data were acquired from 140 hospitals that are part of the Latin American Collaborative Study of Congenital Malformations (ECLAMC) network. The analytical sample included 56,014 live-born infants (∼69% of total sample) with complete data born without congenital anomalies in the years 1996–2011 in Brazil, Argentina, Chile, Venezuela, Ecuador, Colombia, Bolivia, and Uruguay. Prenatal care visits were significantly (at p<.05) and positively associated with BW and negatively associated with LBW for all countries. The OLS coefficients ranged from 9 grams per visit in Bolivia to 36 grams in Uruguay. The association with LBW was strongest for Chile (OR = 0.87 per visit) and lowest for Argentina and Venezuela (OR = 0.95). The association decreased in the recent decade compared to earlier years. Our findings suggest that estimates of association between prenatal care and fetal growth are population-specific and may not be generalizable to other populations. Furthermore, as one of the indicators for a country’s healthcare system for maternal and child health, prenatal care is a highly variable indicator between countries in South America.

Fetal health shocks and early inequalities in health capital accumulation

Several studies report socioeconomic inequalities in child health and consequences of early disease. However, not much is known about inequalities in health capital accumulation in the womb in response to fetal health shocks, which is essential for finding the earliest sensitive periods for interventions to reduce inequalities. We identify inequalities in birth weight accumulation as a result of fetal health shocks from the occurrence of one of the most common birth defects, oral clefts, within the first 9 weeks of pregnancy, using quantile regression and two datasets from South America and the USA. Infants born at lower birth weight quantiles are significantly more adversely affected by the health shock compared with those born at higher birth weight quantiles, with overall comparable results between the South American and US samples. These results suggest that fetal health shocks increase child health disparities by widening the spread of the birth weight distribution and that health inequalities begin in the womb, requiring interventions before pregnancy.

A quasi-experimental analysis of maternal altitude exposure and infant birth weight

OBJECTIVES

We analyzed singleton births to determine the relationship between birth weight and altitude exposure.

METHODS

We analyzed 715,213 singleton births across 74 counties from the western states of Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, and Washington from January 1, 2000, to December 31, 2000. Birth data were obtained from the Division of Vital Statistics, National Center for Health Statistics, for registered births.

RESULTS

Regression analyses supported previous research by showing that a 1000-meter increase in maternal altitude exposure in pregnancy was associated with a 75.9-gram reduction in birth weight (95% confidence interval = -84.1, -67.6). Quantile regression models indicated significant and near-uniform depressant effects from altitude exposure across the conditional distribution of birth weight. Bivariate sample-selection models showed that a 1000-meter increase in altitude exposure, over and above baseline residential altitude, decreased birth weight by an additional 58.8 grams (95% confidence interval = -98.4, -19.2).

CONCLUSIONS

Because of calculable health care-related costs associated with lower birth weight, our reported results might be of interest to clinicians practicing at higher altitudes.

Altitude effects on growth of indigenous children in Oaxaca, Southern Mexico

The effect of altitude of residence on the growth status of 11,454 indigenous school children 6-14 years of age in Oaxaca, southern Mexico, was examined. Indicators of living conditions (human development index [HDI], index of community nutritional risk [INR], index of marginalization [IM], index of relative isolation [II]) were regressed on z-scores for height, weight and BMI, and the residuals were regressed on altitude of residence (km). Independent of other environmental conditions, altitude negatively affected height by approximately -0.07 z-scores per kilometer altitude above sea level. The estimated average decrease in stature was 0.92 cm per kilometer elevation. BMI was significantly increased, 1.2 units per kilometer elevation, consistent with earlier studies of growth status and altitude. In contrast, weight was not affected by altitude of residence. Approximately 36% of the reduction in height and 54% of the increase in BMI were due to altitude effects; the remaining changes in height and BMI were associated with environmental factors reflected in the indices of community well-being considered.

Child health insurance coverage and household activity toward child development in four South American countries

We evaluate the association between child health insurance coverage and household activities that enhance child development. We use micro-level data on a unique sample of 2,370 children from four South American countries. Data were collected by physicians via in-person interviews with the mothers. The regression models compare insured and uninsured children seen within the same pediatric care practice for routine well-child care and adjust for several demographic and socioeconomic characteristics. We also stratify these analyses by selective household demographic and socioeconomic characteristics and by country. We find that insurance coverage is associated with increasingly engaging the child in development-enhancing household activity in the total sample. This association significantly varies with ethnic ancestry and is more pronounced for children of Native or African ancestry. When stratifying by country, a significant positive association is observed for Argentina, with two other countries having positive but insignificant associations. The results suggest that insurance coverage is associated with enhanced household activity toward child development. However, other data and research are needed to estimate the causal relationship.

Living on higher ground reduces child neurodevelopment-evidence from South America

OBJECTIVE

To study the effects of altitude on infant neurodevelopment in the first 2 years of life.

STUDY DESIGN

Data from a unique study of normal infant neurodevelopment in 5 South American countries were used. The sample included 2116 infants 3-24 months of age who were evaluated for neurodevelopmental problems by study physicians during their routine well-child visits at 31 pediatric practices. We used regression models with country fixed-effects that compare the neurodevelopment of children born at different altitudes within the same country to avoid confounding. The regressions adjust for several socioeconomic and demographic factors. We also evaluated altitude effects stratifying by sex, age, and household wealth. Infant neurodevelopment was evaluated by physicians by using the Bayley Infant Neurodevelopmental Screener. The primary outcome is an indicator for whether the infant is at high risk for neurodevelopmental problems based on the Bayley Infant Neurodevelopmental Screener norms.

RESULTS

Altitude significantly increases the probability of being at high risk for neurodevelopmental problems (100-meter increase in altitude: OR 1.02; 95% CI 1.001-1.037; high altitude greater than 2600 meters vs low altitude less than 800 meters: OR 2.01; 95% CI 1.36-2.973). The effects are larger for females and for second than first year of life. The largest effect is for females 12-24 months of age (high vs low altitude: OR 4.147; 95% CI 1.466-12.013). There are no significant differences in altitude effects by household wealth.

CONCLUSIONS

Altitude may significantly increase the risk of neurodevelopmental problems during the first 2 years of life, especially for females during their second year of life.

Explaining racial disparities in infant health in Brazil

OBJECTIVES

We sought to quantify how socioeconomic, health care, demographic, and geographic effects explain racial disparities in low birth weight (LBW) and preterm birth (PTB) rates in Brazil.

METHODS

We employed a sample of 8949 infants born between 1995 and 2009 in 15 cities and 7 provinces in Brazil. We focused on disparities in LBW (< 2500 g) and PTB (< 37 gestational weeks) prevalence between infants of African ancestry alone or African mixed with other ancestries, and European ancestry alone. We used a decomposition model to quantify the contributions of conceptually relevant factors to these disparities.

RESULTS

The model explained 45% to 94% of LBW and 64% to 94% of PTB disparities between the African ancestry groups and European ancestry. Differences in prenatal care use and geographic location were the most important contributors, followed by socioeconomic differences. The model explained the majority of the disparities for mixed African ancestry and part of the disparity for African ancestry alone.

CONCLUSIONS

Public policies to improve children's health should target prenatal care and geographic location differences to reduce health disparities between infants of African and European ancestries in Brazil.

Birthweight outcomes in Bolivia: the role of maternal height, ethnicity, and behavior

We identify maternal behavioral factors associated with birthweight in Bolivia using data from the Demographic and Health Survey (DHS) of 2003. We estimate birthweight as a function of maternal behavior and the child's sex and gestational age. We control for maternal height, ethnicity, education, and wealth, and for differences observed across Bolivian regions in educational and health outcomes, demographic indicators, and altitude. We find that maternal age, fertility record, and birth spacing behavior are the main observable behavioral factors associated with birthweight, and that maternal height is associated with gestational age, a main determinant of birthweight. We also find that after controlling for gestational age, both ethnicity and altitude have an insignificant effect on birthweight.

Hospital volume and mortality of very low-birthweight infants in South America

OBJECTIVE

To assess the effects of hospital volume of very low-birthweight (VLBW) infants on in-hospital mortality of VLBW and very preterm birth (VPB) infants in South America.

DATA SOURCES/STUDY SETTING

Birth-registry data for infants born in 1982-2008 at VLBW or very preterm in 66 hospitals in Argentina, Brazil, and Chile.

DESIGN

Regression analyses that adjust for several individual-level demographic, socioeconomic, and health factors; hospital-level characteristics; and country-fixed effects are employed.

DATA COLLECTION/EXTRACTION METHODS

Physicians interviewed mothers before hospital discharge and abstracted hospital medical records using similar methods at all hospitals.

PRINCIPAL FINDINGS

Volume has significant nonlinear beneficial effects on VLBW and VPB in-hospital survival. The largest survival benefits--more than 80 percent decrease in mortality rates--are with volume increases from low to medium or medium-high levels (from ≤ 25 to 72 infants annually) with significantly lower incremental benefits thereafter. The cumulative volume effects are maximized at the 121-144 annual VLBW infant range--about 90 percent decrease in mortality rates compared to <25 VLBW infants annually.

CONCLUSIONS

Increasing the access of pregnancies at-risk of VLBW and VPB to medium- or high-volume hospitals up to 144 VLBW infants per year may substantially improve in-hospital infant survival in the study countries.

Child health insurance and early preventive care in three South American countries

Not much is known about how health insurance affects preventive care for children who have access to general routine paediatric care, especially in less developed settings. This study evaluates the effects of child health insurance on preventive care (measured by whether the child had received all the age-appropriate immunizations) for children with access to routine paediatric care. It uses a unique sample of 1958 children aged 3-24 months attending paediatric practices for routine well-child care in Argentina, Brazil and Ecuador. It compares insured and uninsured children attending the same paediatric clinics for routine care at the time of enrolment into the study and only uses within-clinic variation in insurance status when evaluating its effect on immunization status. Regression models for adequate immunization status adjust for several demographic, socio-economic and health characteristics and are estimated both separately for each country and combining the three countries. The majority of children in the study sample have received all age-appropriate immunizations. However, publicly insured children in Argentina and Ecuador are more likely to have received all age-appropriate immunizations compared with uninsured children by 3.5 and 2.3 percentage points, respectively. In the model that combines the three country samples, insured children (regardless of insurance type) are significantly more likely to have adequate immunization status by 2.5 percentage points compared with uninsured children. The study provides evidence that health insurance may enhance preventive care for young children.

Application of neurodevelopmental screening to a sample of South American infants: the Bayley Infant Neurodevelopmental Screener (BINS)

OBJECTIVE

To evaluate the utility of the Bayley Infant Neurodevelopmental Screener (BINS), standardized in the US, for South American infants, 3-24 months of age.

METHODS

Thirty-five physicians administered the BINS to 2471 South American infants recruited during routine well-child visits, 578 (23%) from Brazil and 1893 (77%) from six other South American countries. The BINS was translated into Spanish and Portuguese and participating physicians were trained to administer the BINS. Physician inter-rater agreement with training tapes was 84.4%; test-retest reliability for age item sets ranged from 0.80 to 0.93 (Pearson's r). Infants were classified into being at low, moderate, or high risk for developmental delay or neurological impairment based on their total BINS score. The sample was stratified by infant's age, sex and language (Spanish and Portuguese). The BINS scores were compared to the scores of the US infant sample used to standardize the BINS.

RESULTS

Female infants performed higher than male at 16-20 months and 21-24 months; male infant scores were more variable at 5-6 months. Scores on only two items were significantly different between Spanish and Portuguese speaking participants. South American scores were typically significantly higher than the US sample, and a lower proportion of infants were classified as being at high risk in the South American sample than in the US standardization sample.

CONCLUSION

Overall, the results of this study indicate that the BINS is feasible and appropriate for neurodevelopmental screening in South America. Further studies are needed to confirm the BINS utility in South America, including its use with a clinical sample.

Climate variability and child height in rural Mexico

We examine the impacts of weather shocks, defined as rainfall or growing degree days, a cumulative measure of temperature, more than a standard deviation from their respective long run mean, on the stature of children between 12 and 47 months of age in Mexico. We find that after a positive rainfall shock children are shorter regardless of their region or altitude. Negative temperature shocks have a negative impact on height in the central and southern parts of the country as well as in higher altitudes. Although on average there are no statistically significant impacts from positive temperature shocks, certain sub-populations - namely boys, children between 12 and 23 months at the time of measurement, and children of less educated mothers - in some of the regions are negatively impacted. The results also suggest that potentially both agricultural income and communicable disease prevalence contribute to the effects.

The Impact of Household Investments on Early Child Neurodevelopment and on Racial and Socioeconomic Developmental Gaps - Evidence from South America

This paper assesses the effects of household investments through child educating activities on child neurodevelopment between the ages of 3 and 24 months, and evaluates whether investments explain racial and socioeconomic developmental gaps in South America. Quantile regression is used to evaluate the heterogeneity in investment effects by unobserved developmental endowments. The study finds large positive investment effects on early child neurodevelopment, with generally larger effects among children with low developmental endowments (children at the left margin of the development distribution). Investments explain part of the observed racial gaps and the whole socioeconomic developmental gap. Investments may compensate for low endowments and policy interventions to increase investments may reduce early development gaps and result in high social and economic returns.

The effect of systematic pediatric care on neonatal mortality and hospitalizations of infants born with oral clefts

Background

Cleft lip and/or palate (CL/P) increase mortality and morbidity risks for affected infants especially in less developed countries. This study aimed at assessing the effects of systematic pediatric care on neonatal mortality and hospitalizations of infants with cleft lip and/or palate (CL/P) in South America.

Methods

The intervention group included live-born infants with isolated or associated CL/P in 47 hospitals between 2003 and 2005. The control group included live-born infants with CL/P between 2001 and 2002 in the same hospitals. The intervention group received systematic pediatric care between the 7^th and 28^th day of life. The primary outcomes were mortality between the 7^th and 28^th day of life and hospitalization days in this period among survivors adjusted for relevant baseline covariates.

Results

There were no significant mortality differences between the intervention and control groups. However, surviving infants with associated CL/P in the intervention group had fewer hospitalization days by about six days compared to the associated control group.

Conclusions

Early systematic pediatric care may significantly reduce neonatal hospitalizations of infants with CL/P and additional birth defects in South America. Given the large healthcare and financial burden of CL/P on affected families and the relatively low cost of systematic pediatric care, improving access to such care may be a cost-effective public policy intervention.

Trial Registration

ClinicalTrials.gov: NCT00097149

Racial gaps in child health insurance coverage in four South American countries: the role of wealth, human capital, and other household characteristics

OBJECTIVE. To evaluate the extent of racial gaps in child health insurance coverage in South America and study the contribution of wealth, human capital, and other household characteristics to accounting for racial disparities in insurance coverage. DATA SOURCES/STUDY SETTING. Primary data collected between 2005 and 2006 in 30 pediatric practices in Argentina, Brazil, Ecuador, and Chile. DESIGN. Country-specific regression models are used to assess differences in insurance coverage by race. A decomposition model is used to quantify the extent to which wealth, human capital, and other household characteristics account for racial disparities in insurance coverage. DATA COLLECTION/EXTRACTION METHODS. In-person interviews were conducted with the mothers of 2,365 children. PRINCIPAL FINDINGS. The majority of children have no insurance coverage except in Chile. Large racial disparities in insurance coverage are observed. Household wealth is the single most important household-level factor accounting for racial disparities in coverage and is significantly and positively associated with coverage, followed by maternal education and employment/occupational status. Geographic differences account for the largest part of racial disparities in insurance coverage in Argentina and Ecuador. CONCLUSIONS. Increasing the coverage of children in less affluent families is important for reducing racial gaps in health insurance coverage in the study countries.

The Impact of Maternal Smoking during Pregnancy on Early Child Neurodevelopment

Early child neurodevelopment has major impacts on future human capital and health. However, not much is known about the impacts of prenatal risk factors on child neurodevelopment. This study evaluates the effects of maternal smoking during pregnancy on child neurodevelopment between 3 and 24 months of age and interactions with socioeconomic status (SES). Data from a unique sample of children from South America are employed. Smoking has large adverse effects on neurodevelopment, with larger effects in the low SES sample. The study results highlight the importance of early interventions beginning before and during pregnancy for enhancing child development and future human capital attainment.