Risk factors for the increasing trend in low birth weight among live births born by vaginal delivery, Brazil

Impact of socioeconomic factors and health determinants on preterm birth in Brazil: a register-based study

BACKGROUND

More than 15 million children are born preterm annually. While preterm survival rates have increased in high-income countries. Low- and middle-income countries, like Brazil, continue to battle high neonatal mortality rates due to a lack of adequate postnatal care. Globally, neonatal mortality is higher for preterm infants compared to those born at term. Our study aims to map and analyze the spatial, socioeconomic, and health coverage determinants related to preterm birth in Brazil in order to understand how spatial variations in demographics and access to primary care may affect preterm birth occurrences.  METHODS: Using publicly available national-level data from the Brazilian health system for 2008-2017, we conducted an ecological study to visualize the spatial distributions of preterm birth along with socioeconomic status, the structure of health services, and primary care work process, each consisting of multiple variables reduced via principal component analysis. Regression models were created to determine predictive effects of numeric and spatial variation of these scores on preterm birth rates.

RESULTS

In Brazil, preterm birth rates increased from 2008-2017, with small and rural municipalities frequently exhibiting higher rates than urban areas. Scores in socioeconomic status and work process were significant predictors of preterm birth rates, without taking into account spatial adjustment, with more positive scores in socioeconomic status predicting higher preterm birth rates (coefficient 0.001145) and higher scores in work process predicting lower preterm birth rates (coefficient -0.002416). Geographically weighted regression showed socioeconomic status to be a more significant predictor in the North, with the work process indicators being most significant in the Northeast.

CONCLUSIONS

Results support that primary care work process indicators are more significant in estimating preterm birth rates than physical structures available for care. These results emphasize the importance of ensuring the presence of the minimum human resources needed, especially in the most deprived areas of Brazil. The association between social determinants of health and preterm birth rates raises questions regarding the importance of policies dedicated to foster equity in the accessibility of healthcare services, and improve income as protective proxies for preterm birth.

Maternal smoking status during pregnancy and low birth weight in offspring: systematic review and meta-analysis of 55 cohort studies published from 1986 to 2020

BACKGROUND

Maternal smoking during pregnancy may be associated with low birth weight (LBW) in offspring and global risk estimates have not been summarized previously. We aimed to systematically explore evidence regarding maternal smoking and the LBW risk in offspring globally and examine possible causes of heterogeneity across relevant studies.

METHODS

Comprehensive search of PubMed, Ovid Embase, Ovid Medline (R), and Web of science from inception until October 2021 was carried out. A random-effects meta-analysis was used to estimate the pooled odds ratio (OR) and corresponding 95% confidence interval (CI). Restricted cubic spline analysis with three knots was used to further examine the dose-response relationship.

RESULTS

Literature searches yielded 4940 articles, of which 53 met inclusion criteria (comprising 55 independent studies). Maternal smoking during pregnancy was significantly associated with the risk of LBW in offspring (OR = 1.89, 95% CI = 1.80-1.98). Furthermore, an obvious dose-response relationship between the amount of cigarettes daily smoked in pregnancy and the risk of LBW in offspring was observed. The results of subgroup analyses indicated that the risk of maternal smoking on LBW was larger in more recently conducted studies (P = 0.020) and longer period of active smoking during pregnancy (P = 0.002). No evidence of publication bias was found.

CONCLUSIONS

In summary, maternal smoking in pregnancy was significantly associated with a higher risk of LBW in offspring on a global scale. The risk of maternal smoking on infant LBW seems to be increasing over time, and was higher with longer smoking duration throughout pregnancy and more cigarettes smoked daily.

Individual and contextual socioeconomic status as effect modifier in the air pollution-birth outcome association

BACKGROUND

Several studies have examined whether air pollution is associated with adverse births outcomes, but it is not clear if socioeconomic status (SES) modifies this relationship.

OBJECTIVES

We investigated if maternal education and area-level socioeconomic status modified the relationship between ozone, nitrogen dioxide and particulate matter with aerodynamic diameter <10 μm (PM₁₀) on preterm births (PTB; gestational age <37 weeks) and term low birth weight (TLBW; weight < 2500 g on term deliveries).

METHODS

Analyses were based on almost 1 million singleton live births in São Paulo municipality between 2011 and 2016. The final sample included 979,306 births for PTB analysis and 888,133 for TLBW analysis. Exposure to PM₁₀, NO₂ and O₃ were based on date of birth and estimated for the entire gestation and for each trimester. Multilevel logistic regression models were conducted to examine the effect of air pollutants on both adverse birth outcomes and whether it was modified by individual and area-level SES.

RESULTS

In fully adjusted models, over the entire pregnancy, a 10 μg/m³ increase in O₃ and PM₁₀ was associated with increased chance of PTB (odds ratio; OR = 1.14 CI 1.13, 1.16 and 1.08 CI = 1.02, 1.15 respectively) and PM₁₀ with TLBW (OR = 1.08 CI 1.03, 1.14). Associations were modified by maternal educational and area-level SES for both outcomes. Mothers of lower education had an additional chance of PTB and TLBW due to PM₁₀ exposure (OR = 1.04 CI 1.04, 1.05 and 1.10 CI 1.08, 1.14 respectively), while mothers living in low SES areas have an additional chance for TLBW (OR = 1.05 CI 1.03, 1.06). Similar modification effects were found for O₃ exposure. Trimester specific associations were weaker but followed a similar pattern.

CONCLUSION

Socioeconomic status modifies the effect of air pollution on adverse birth outcomes. Results indicate that mothers with lower SES may be more susceptible to air pollution effects.

Maternal and neonatal factors associated with low birth weight among neonates delivered at the University of Gondar comprehensive specialized hospital, Northwest Ethiopia

INTRODUCTION

Low birth weight is a major contributory factor to infant mortality. Although low birth weight remains an important public health problem in Ethiopia, little emphasis is paid to its intervention as a means of reducing neonatal mortality. The aim of this study was to assess the magnitude of low birth weight and its associated maternal and neonatal factors in newborns delivered at the University of Gondar Comprehensive Specialized Hospital.

METHODS

Hospital-based cross-sectional study was conducted, and 481 study participants were selected using systematic random sampling methods. Pre-tested interviewer-administered questionnaires were used to collect the data. Bivariable and multivariable binary logistic regression was implemented. Finally, the odds ratio with a 95% CI and a p-value of <0.05 were used to identify factors associated with low birth weight.

RESULT

The prevalence of low birth weight was 12.5% (95% CI; 9.8, 15.7%). Preterm birth (AOR = 38; 95% CI: 15.3, 93.0), pregnancy-induced hypertension (PIH) (AOR = 2.6; 95%CI: 1.1, 6.4), maternal body mass index (BMI) of < 18.5 kg/m² (AOR = 6.8; 95% CI: 1.5, 31.1), and grand multiparity (AOR = 4.2; 95% CI: 1.2, 16) were factors positively associated with low birth weight. However, babies delivered from mothers with age > 35 years (AOR = 0.14:95% CI 0.03, 0.7) had lower odds of low birth weight.

CONCLUSION

In this study, the prevalence of low birth weight was higher than in the previous studies. The study revealed preterm birth, PIH, BMI of < 18.5 kg/m², and grand multiparity were independent factors that increase the low birth weight while maternal age > 35 years reduces the low birth weight. Therefore, healthcare professionals should emphasize the early identification and management of women with PIH, tackling prematurity, and preventing maternal malnutrition through nutritional counseling as much as possible.

The Association Between Birth Weight and Fat, Sugar, and Vegetable Consumption in a National Sample of U.S. Preschool Age Children

INTRODUCTION

Adverse prenatal development is a contributor to obesity susceptibility in children. Dietary behavior is one mechanism through which adverse prenatal development may promote obesity, but evidence for the role of prenatal overnutrition in dietary intake in young children is scant.

METHODS

We used data from the National Health and Nutrition Examination Survey 2009-2014. Our study sample included 1782 U.S. children 2-5 years old with available birth weight and two 24-h dietary recalls. We used linear and Poisson regression to examine the association of birth weight (LBW < 2500 g, HBW > 4100 g) and 2-day average intake of dietary variables. We tested interactions between birthweight and breastfeeding (breastfed > 5 months vs. not breastfed or breastfed 0-5 months), and report breastfeeding-specific results.

RESULTS

In multivariable regression analysis, in boys, LBW was associated with 2.4 (95% CI - 4.3, - 0.5) lower percent of kcal from solid fat; lower sugar intake, marginally lower saturated and total fat intake, and 0.6 cup (95% CI 0.1, 1.0) greater vegetable consumption; HBW was marginally associated with lower fat. Birth weight was unrelated to diet in girls. Breastfeeding modified associations between birth weight and dietary intake, but the direction of modification was mixed.

DISCUSSION

Our findings do not support the hypothesis that LBW or HBW are associated with adverse diet consumption in preschool age U.S. children. Improved understanding of the role of early life development of dietary behavior requires further research on the development of appetitive traits and the role of the family and preschool food environments.

Urban social environment and low birth weight in 360 Latin American cities

OBJECTIVE

Using data compiled by the SALURBAL project (Urban Health in Latin America; 'Salud Urbana en América Latina') we quantified variability in low birth weight (LBW) across cities in Latin America, and evaluated the associations of socio-economic characteristics at various levels (maternal, sub-city and city) with the prevalence of LBW.

METHODS

The sample included 8 countries, 360 cities, 1321 administrative areas within cities (sub-city units) and birth registers of more than 4.5 million births for the year 2014. We linked maternal education from birth registers to data on socioeconomic characteristics of sub-cities and cities using the closest available national population census in each country. We applied linear and Poisson random-intercept multilevel models for aggregated data.

RESULTS

The median prevalence of city LBW by country ranged from a high of 13% in Guatemala to a low of 5% in Peru (median across all cities was 7.8%). Most of the LBW variability across sub-cities was between countries, but there were also significant proportions between cities within a country, and within cities. Low maternal education was associated with higher prevalence of LBW (Prevalence rate ratios (PRR) for less than primary vs. completed secondary or more 1.12 95% CI 1.10, 1.13) in the fully adjusted model. In contrast, higher sub-city education and a better city social environment index were independently associated with higher LBW prevalence after adjustment for maternal education and age, city population size and city gross domestic product (PRR 1.04 95% CI 1.03, 1.04 per SD higher sub-city education and PRR 1.02 95% CI 1.00, 1.04 per SD higher SEI). Larger city size was associated with a higher prevalence of LBW (PRR 1.06; 95% CI 1.01, 1.12).

CONCLUSION

Our findings highlight the presence of heterogeneity in the distribution of LBW and the importance of maternal education, local and broader social environments in shaping LBW in urban settings of Latin America. Implementing context-sensitive interventions guided to improve women's education is recommended to tackle LBW in the region.

Mean birth weight among term newborns: direction, magnitude and associated factors

A trend towards increasing birth weight has been shown, but factors that explain these trends have not been elucidated. The objectives of this study were to evaluate changes in mean birth weight of term newborns and to identify factors associated with them. All cohorts are population-based studies in which random samples of births (Ribeirão Preto, São Paulo State in 1978/1979, 1994 and 2010; Pelotas, Rio Grande do Sul State in 1982, 1993 and 2004; and São Luís, Maranhão State in 1997/1998 and 2010, Brazil). A total of 32,147 full-term, singleton live births were included. Mean birth weight reduced in the first study period (-89.1g in Ribeirão Preto from 1978/1979 to 1994, and -27.7g in Pelotas from 1982 to 1993) and increased +30.2g in Ribeirão Preto from 1994 to 2010 and +24.7g in São Luís from 1997 to 2010. In the first period, in Ribeirão Preto, mean birth weight reduction was steeper among mothers with high school education and among those born 39-41 weeks. In the second period, the increase in mean birth weight was steeper among mothers with low schooling in Ribeirão Preto and São Luís, females and those born 37-38 weeks in Ribeirão Preto and cesarean section in São Luís. Birth weight decreased in the first study period then increased thereafter. The variables that seem to have been able to explain these changes varied over time.

Maternal Active Smoking During Pregnancy and Low Birth Weight in the Americas: A Systematic Review and Meta-analysis

Introduction

Smoking during pregnancy may negatively impact newborn birth weight. This study investigates the relationship between maternal active smoking during pregnancy and low birth weight in the Americas through systematic review and meta-analysis.

Methods

A literature search was conducted through indexed databases and the grey literature. Case-control and cohort studies published between 1984 and 2016 conducted within the Americas were included without restriction regarding publication language. The article selection process and data extraction were performed by two independent investigators. A meta-analysis of random effects was conducted, and possible causes of between-study heterogeneity were evaluated by meta-regressions and subgroup analyses. Publication bias was assessed by visual inspection of Begg's funnel plot and by Egger's regression test.

Results

The literature search yielded 848 articles from which 34 studies were selected for systematic review and 30 for meta-analysis. Active maternal smoking was associated with low birth weight, OR = 2.00 (95% CI: 1.77-2.26; I2 = 66.3%). The funnel plot and Egger's test (p = .14) indicated no publication bias. Meta-regression revealed that sample size, study quality, and the number of confounders in the original studies did not account for the between-study heterogeneity. Subgroup analysis indicated no significant differences when studies were compared by design, sample size, and regions of the Americas.

Conclusion

Low birth weight is associated with maternal active smoking during pregnancy regardless of the region in the Americas or the studies' methodological aspects.

Implications

A previous search of the major electronic databases revealed that no studies appear to have been conducted to summarize the association between maternal active smoking during pregnancy and low birth weight within the Americas. Therefore, this systematic review may help to fill the information gap. The region of the Americas contains some of the most populous countries in the world; therefore, this study may provide useful data from this massive segment of the world's population.

Air pollution and low birth weight in an industrialized city in Southeastern Brazil, 2003-2006

ABSTRACT: Introduction: Birth weight is an important indicator of several conditions that manifest earlier (as fetal and neonatal mortality and morbidity, inhibited growth and cognitive development) and later in life such as chronic diseases. Air pollution has been associated with adverse pregnancy outcomes. Objective: Retrospective cohort study investigated the association between low birth weight (LBW) and maternal exposure to air pollutants in Volta Redonda city, Rio de Janeiro, Brazil, from 2003 to 2006. Methods: Birth data was obtained from Brazilian Information System. Exposure information (O3, PM10, temperature and humidity) was provided by Governmental Air Quality Monitoring System. Linear and Logistic models, adjusted for sex, type of pregnancy, prenatal care, place of birth, maternal age, parity, education, congenital anomalies and weather variables were employed. Results: Low birth weight (LBW) represented 9.1% of all newborns (13,660). For an interquartile range increase in PM10 it was found OR2 ndTrimester = 1.06 (95%CI 1.02 - 1.10), OR3 rdTrimester = 1.06 (95%CI 1.02 - 1.10) and, in O3 it was found OR2 ndTrimester = 1.03 (95%CI 1.01 - 1.04), OR3 rdTrimester = 1.03 (95%CI 1.02 - 1.04). The dose-response relationship and a reduction in birth weight of 31.11 g (95%CI -56.64 - -5.58) was observed in the third trimester of pregnancy due to an interquartile increase of O3. Conclusion: This study suggests that exposures to PM10 and O3, even being below the Brazilian air quality standards, contribute to risks of low birth weight.

Prevalence and Risk Factors of Low Birth Weight in the Southeast of Iran

BACKGROUND

The purpose of this study was to determine the prevalence and related factors of low birth weight (LBW) in the Southeast of Iran.

METHODS

This cross-sectional study was carried out in Kerman province. Data were collected from Iranian Maternal and Neonatal Network at public and private hospitals. All live births from March 2014 to March 2015 considered as the source population. The risk factors including maternal age, gravida, parity, abortion, pregnancy risk factors, maternal nationality, maternal education, maternity insurance, place of living, consanguinity, neonate sex, preterm labor, place of birth, delivery manager, and delivery type were compared between LBW and normal birth weight groups.

RESULTS

The prevalence of LBW was 9.4% in the present study. Preterm labor (odds ratio [OR]: 22.06; P < 0.001), neonate female sex (OR: 1.41; P < 0.001), low parity (OR: 0.85; P < 0.001), pregnancy age <18 years (OR: 1.26; P = 0.012), pregnancy age >35 years (OR: 1.21; P = 0.001), delivery by cesarean section (OR: 1.17; P = 0.002), pregnancy risk factors (OR: 1.67; P < 0.001), maternal illiteracy (OR: 1.91; P < 0.001), living in the rural area (OR: 1.19; P < 0.001), consanguineous (OR: 1.08; P = 0.025), and delivery by obstetrician (OR: 1.12; P = 0.029) were identified as significant factors associated with LBW in this study.

CONCLUSIONS

Prevention of preterm labor, consanguineous marriage, pregnancy age <18 and >35 years old, and maternal medical risk factors are some critical interventions to reduce its burden. Increasing the access to high-quality health-care services in rural and deprived areas is another effective strategy for the prevention of LBW.

Changes in perinatal health in two birth cohorts (1997/1998 and 2010) in São Luís, Maranhão State, Brazil

The objective of this study was to analyze changes in perinatal health in two birth cohorts started in 1997/1998 and 2010, respectively, in São Luís, Maranhão State, Brazil. A total of 2,493 live born infants were included in 1997/1998 and 5,166 in 2010. Low birth weight (LBW) rate did not change (8.5% in 1997/1998 and 8.6% in 2010). Preterm birth (PTB) rate also remained stable (13.2% in 1997/1998 and 13% in 2010). Teenage deliveries and births to single mothers decreased. Maternal schooling and prenatal care coverage increased. Intrauterine growth restriction (IUGR) decreased from 13.3% to 10.6% (p < 0.001). The perinatal mortality rate decreased from 36.6 to 20.7 per 1,000 (p < 0.001) and the infant mortality rate (IMR) dropped from 28.5 to 12.8 per 1,000 (p < 0.001). The cesarean rate increased from 34.1% to 47.5% (p < 0.001). In conclusion, despite favorable changes in socio-demographic, behavioral, and health service factors and decreasing rates of IUGR and perinatal and infant mortality, LBW and PTB remained stable, while the cesarean rate increased.

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.

Low birth weight at term and the presence of fine particulate matter and carbon monoxide in the Brazilian Amazon: a population-based retrospective cohort study

BACKGROUND

Although studies have shown an association between air pollutants from anthropogenic sources and pregnancy outcomes, little is known regarding the association between low birth weight (LBW) and exposure to emissions of biomass burning.

METHODS

This population-based retrospective cohort study assessed the effect of exposure to particulate matter and carbon monoxide (CO) from biomass burning in the Amazon and cerrado (Brazilian savanna) biomes on term LBW (<2500 g) in cities of Mato Grosso, Brazil. Data on births were obtained from the Information System on Live Births of the Ministry of Health. The exclusion criteria were a twin pregnancy, gestational age of less than 37 weeks, and congenital malformation diagnosed at birth. For exposure variables, we used a historical series of daily average concentrations of particulate matter with a diameter less than 2.5 μm (PM2.5) and CO provided by Coupled Aerosol and Trace Gases Transport Model for the Brazilian Development of the Regional Atmospheric Modeling System developed at the National Institute for Space National Center for Weather Forecasts and Climate Studies, National Institute for Space Research. Maternal exposure was estimated by the average amount of pollutants for each trimester and for the entire period of gestation. The association between air pollutants and LBW was analyzed by multiple logistic regression, adjusting for the newborn's sex, mother's age and education, and prenatal care.

RESULTS

A total of 6147 full-term singleton live births were included in the study and 193 (3.1%) were LBW. In adjusted analysis, the number of prenatal visits and maternal education with 8 years or more were associated with LBW. The association between exposure to air pollutants and the risk of LBW was significant for the 4th quartile of PM2.5 concentrations in the 2nd trimester (OR = 1.51, 95% CI = 1.04 to 2.17) and in the 3rd trimester, and for the 4th quartile of CO concentrations in the 2nd trimester only, in adjusted analysis.

CONCLUSIONS

This study provides further evidence of the effect of smoke from biomass burning on the occurrence of LBW in cities of the Brazilian Amazon.

Current pattern of Ponderal Indices of term small-for-gestational age in a population of Nigerian babies

Background

Small-for-gestational age (SGA) newborns constitute a special group of neonates who may have suffered varying degrees of intrauterine insults and deprivation. Variations in birth weight, length and Ponderal Index (PI) depend on the type and degree of intrauterine insults the babies were exposed to. The objective of the study was to determine the current prevalence of term SGA births in a Nigerian Tertiary Hospital and the current pattern of Ponderal Indices among term SGA in a population of Nigerian babies.

Methods

Subjects comprised of consecutive term singleton mother-baby pairs in the first 24 hours of life. It was a cross sectional study. The anthropometric parameters of each baby were recorded and the PI was also determined.

Results

Out of 1,052 live births during the study period (September to December, 2009), 825 were term, singleton babies. Five hundred and eight-one babies (70.4%) fall into the upper socio-economic classes 1 and II, 193 (23.4%) in the middle class and 51 (6.2%) were of the lower classes IV and V. None of the mothers indicated ingestion of alcohol or smoking of cigarette. Fifty-nine babies (7.2%) were small-for gestational age (SGA). Of the 59 SGA subjects, 26 (44.1%) were symmetrical SGA while 33 (55.9%) were asymmetrical SGA. There was no significant sex or socioeconomic predilection for either symmetrical or asymmetrical growth (p = 0.59, 0.73 respectively).

Conclusion

The findings showed that proportionality in SGA fetuses is a continuum, with the PI depending on the duration of intrauterine insult and the extent of its effects on weight and length before delivery.

Smoking and adverse maternal and child health outcomes in Brazil

INTRODUCTION

Numerous studies from high-income countries document the causal relationship between cigarette smoking during pregnancy and adverse maternal and child health (MCH) outcomes. Less research has been conducted in low and middle income countries, but a burgeoning literature can be found for Brazil.

METHODS

We review Brazilian studies of the prevalence of maternal smoking, the relative risk of smoking-attributable adverse MCH outcomes, and present new estimates for these outcomes, using the attributable fraction method.

RESULTS

We found that Brazilian studies of the relative risks of smoking-attributable adverse MCH outcomes were broadly consistent with previous reviews. Based on a comparison of maternal smoking over time, smoking during pregnancy has declined by about 50% over the last 20 years in Brazil. For 2008, we estimate that 5,352 cases of spontaneous abortion, 10,929 cases of preterm birth, 20,717 cases of low birth weight, and 29 cases of sudden infant death syndrome are attributable to maternal smoking. Between 1989 and 2008, the percent of smoking-attributable adverse MCH outcomes in Brazil was at least halved.

CONCLUSIONS

The results show that over a 20-year period, during which Brazil implemented numerous effective tobacco control measures, the country experienced a dramatic decrease in both maternal smoking prevalence and smoking-attributable adverse MCH outcomes. Countries that implement effective tobacco control measures can expect to reduce both maternal smoking and adverse MCH outcomes, thereby improving the public health.

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.

Saúde da criança: fatores de risco aplicados em programas de atenção básica à saúde

OBJETIVO: comparar as frequências dos fatores de risco em crianças matriculadas em unidades básicas de saúde (UBS) em dois períodos (1988-1989 e 2005-2006) e analisar a associação desses fatores com desnutrição, internação e óbito. MÉTODOS:Estudo de abordagem quantitativa, tipo coorte retrospectiva com amostra probabilística (n=414) de crianças menores de um ano matriculadas em duas UBSs do Embu (SP), em 2005-2006. Variáveis independentes: alto risco e presença de fatores de risco. Desfechos: evolução ponderal desfavorável, déficit nutricional, internação, óbito. Estatística: Qui-Quadrado e Odds Ratio. RESULTADOS: em 2005-2006, verificou-se: maior frequência de intercorrências neonatais e mães adolescentes; menor freqüência de desnutrição ou óbito de irmão < 5 anos; evolução ponderal desfavorável (1,6%); deficit nutricional (2,9%); IMC > 2z (17,9%); internações (21,8%); nenhum óbito. Baixo peso ao nascer associou-se à internação (OR=4,04;IC95%:1,35-12,04). CONCLUSÕES: Baixo peso ao nascer permanece, como importante fator de risco e a proporção de sobrepeso/obesidade indica necessidade de redirecionamento das ações de saúde da criança.

Análise de tendências das taxas de mortalidade infantil e de seus fatores de risco na cidade de Porto Alegre, Rio Grande do Sul, Brasil, no período de 1996 a 2008

Objetiva-se determinar as tendências de mortalidade infantil e de seus fatores de risco em Porto Alegre. Este é um estudo baseado nas informações do registro de nascidos vivos e de óbitos infantis no período de 1996-2008. Foi analisada a tendência temporal das taxas de mortalidade infantil (TMI) e de seus componentes, de acordo com a escolaridade materna, o número de consultas de pré-natal, idade materna, número de filhos vivos e mortos, sexo do recém-nascido, o tipo de parto, a idade gestacional, o peso de nascimento e o tipo de hospital. Foi utilizada a regressão sequencial de Poisson para estimar a influência da condição socioeconômica e os demais fatores de risco. A TMI decaiu entre os nascidos de mães com escolaridade inferior a 11 anos. Entre os nascidos de mães com 12 ou mais anos de escolaridade, não houve alterações significativas. A condição socioeconômica materna foi o fator que mais se associou à redução da mortalidade infantil. Contudo, a tendência de redução não atingiu todo o potencial devido ao aumento do baixo peso ao nascer.

Poluição ambiental, residência materna e baixo peso ao nascer

Estudo caso-controle, que objetivou analisar os fatores de risco associados ao baixo peso ao nascer de recém-nascidos de mães de Rio Grande-RS residentes nas proximidades da área industrial. Foram entrevistadas mães que deram à luz nas maternidades do município, durante os meses de abril a novembro de 2003. A amostra compreendeu 138 casos e 409 controles. Foi realizada análise estatística bivariada e multivariada. O Baixo Peso ao Nascer (BPN) manteve-se associado positivamente com natimortos prévios, BPN prévios, presença de hipertensão arterial durante a gestação e ameaça de aborto durante a gravidez atual. Foi possível identificar os principais fatores de risco a que estão expostas as gestantes e que interferem no peso ao nascer de seus filhos, os quais vêm somar-se àqueles decorrentes de uma maior exposição a poluentes, por residirem próximo às indústrias.

Molecular detection of Treponema pallidum sp. pallidum in blood samples of VDRL-seroreactive women with lethal pregnancy outcomes: a retrospective observational study in northern Brazil

INTRODUCTION

Although control measures of maternal and congenital syphilis are available in Brazil, difficulties exist within the healthcare network in providing a laboratory diagnosis of the infection during the prenatal period. The objective of this study was to confirm the presence of Treponema pallidum by PCR in women with positive VDRL serology and lethal pregnancy outcomes, i.e., abortion, stillbirth and neonatal death.

METHODS

A retrospective study was conducted on VDRLseroreactive women with lethal pregnancy outcomes admitted to the Fundação Santa Casa de Misericórdia do Pará (FSCM-PA) between January and July 2004. Serum samples and DNA from whole blood were obtained at the time of screening by the VDRL test. These samples were analyzed by IgG ELISA, IgM FTA-Abs and simple PCR (polA).

RESULTS

During the study period, 0.7% (36/4,912) of women with lethal pregnancy outcomes presented a positive VDRL test. The polAgene was amplified in 72.7% (24/33) of these women, with 55.6% (20/36) and 94.4% (34/36) presenting IgM and IgG antibodies against T. pallidum, respectively. Comparison of these results showed a significant difference, with agreement between the PCR and IgM FTA-Abs results, suggesting that maternal syphilis was an active infection. No basic cause of death of the conceptus was reported in 97.2% (35/36) of cases. Among women who were submitted to the VDRL test during the prenatal period, only four of the nine seroreactive patients underwent treatment.

CONCLUSIONS

The high frequency of syphilis in the group studied indicates the fragility of the service of infection diagnosis, treatment and monitoring, compromising epidemiological control.

Caracterização das mães, partos e recém-nascidos em Campinas, São Paulo, 2001 e 2005

OBJETIVO: Comparar dados pré-natais, dos partos e dos recém-nascidos de Campinas em 2001 e 2005. MÉTODOS: Estudo transversal que analisou 13.656 documentos do Sistema de Informações sobre Nascidos Vivos (Sinasc) de 2005, comparando-as aos resultados de 2001. Analisou-se o local de moradia e parto, idade materna, estado civil, escolaridade, ocupação, paridade, consultas de pré-natal, tipo de parto, duração da gestação e peso ao nascer. Para avaliar a associação entre as variáveis, utilizou-se o teste de qui-quadrado, sendo significante p<0,05. RESULTADOS: Os nascidos nos Distritos de Saúde (DS) com piores índices de condições de vida (ICV) diminuíram em relação a 2001. A taxa de adolescentes passou de 17,7% para 14,7%. Em 2001, 39,4% das mães trabalhavam e, em 2005, 42,9%. Quanto à presença de companheiro, 35,9 e 54,3% não o referiam em 2001 e 2005, respectivamente. A escolaridade passou de 37,8% de mães com até sete anos de estudo para 25,7%, com aumento das que estudaram entre oito e 11 anos e 12 anos ou mais. O comparecimento a mais de seis consultas no pré-natal passou de 74,4 para 86,6%. Houve aumento de cesáreas (54,9 para 60,3%) e de prematuridade (7,1 para 8,9%). Não houve alteração no perfil de peso ao nascimento. CONCLUSÕES: Verificou-se queda da paridade nos DS com piores ICV e no percentual de mães adolescentes. Elevou-se o número de trabalhadoras, mulheres sem companheiro, escolaridade e frequência ao pré-natal.

Absence of disparities in anthropometric measures among Chilean indigenous and non-indigenous newborns

Background

Studies throughout North America and Europe have documented adverse perinatal outcomes for racial/ethnic minorities. Nonetheless, the contrast in newborn characteristics between indigenous and non-indigenous populations in Latin America has been poorly characterized. This is due to many challenges, including a lack of vital registration information on ethnicity. The objective of this study was to analyze trends in anthropometric measures at birth in Chilean indigenous (Mapuche) and non-indigenous children over a 5-year period.

Methods

We examined weight and length at birth using information available through a national data base of all birth records for the years 2000 through 2004 (n = 1,166.513). Newborns were classified ethnically according to the origins of the parents' last names.

Result

The average birthweight was stable over the 5 year period with variations of less than 20 g in each group, and with mean values trivially higher in indigenous newborns. The proportion weighing less than 2500 g at birth increased modestly from 5.2% to 5.6% in non-indigenous newborns whereas the indigenous births remained constant at 5.2%. In multiple regression analyses, adjusting flexibly for gestational age and maternal characteristics, the occurrence of an indigenous surname added only 14 g to an average infant's birthweight while holding other factors constant. Results for length at birth were similar, and adjusted time trend variation in both outcomes was trivially small after adjustment. Anthropometric indexes at birth in Chile are quite favorable by international standards.

Conclusion

There is only a trivial degree of ethnic disparity in these values, in contrast to conditions for ethnic minorities in other countries. Moreover, these values remained roughly constant over the 5 years of observation in this study.

Qualidade e eqüidade na assistência à gestante: um estudo de base populacional no Sul do Brasil

Estudo de base populacional com objetivo de avaliar a cobertura da assistência pré-natal, de acordo com a renda familiar, em município do Sul do Brasil. As informações foram coletadas por questionário, com as mães nas primeiras 24 horas após o parto. Observa-se que a cobertura pré-natal, o inicio das consultas no primeiro trimestre, a realização de seis consultas ou mais, a execução do exame das mamas e do exame especular, a realização dos exames de laboratório da rotina pré-natal do Programa de Humanização no Pré-natal e Nascimento (PHPN) e a realização da ultra-sonografia, aumentam com a melhoria da renda familiar, sendo mais realizados nas gestantes do quartil de maior renda (p < 0,001). Apesar destes resultados, a prevalência de baixo peso ao nascer não apresentou diferença estatística significante entre os diferentes quartis. O serviço local de saúde mostrou-se pouco efetivo porque apenas 26,8% dos pré-natais foram classificados como adequados, segundo parâmetros do PHPN, e desigual porque as pacientes do menor quartil de renda tiveram o acompanhamento da sua gestação com qualidade inferior à das pacientes do quarto quartil.

SECULAR TREND OF VERY LOW BIRTH WEIGHT RATE IN PORTO ALEGRE, SOUTHERN BRAZIL

The strong association of very low birth weight (VLBW; <1500 g) with infant mortality is well known. There are no data related to VLBW trends in Brazil although findings from some large surveys carried out in small- and medium-sized cities have demonstrated an increase in low birth weight (LBW; <2500 g) rates over the last 30 years. The aim of this study was to evaluate the secular trend of VLBW in the city of Porto Alegre, a large city in a developed area in southern Brazil, and the potential determinants of this trend during the 1990s and early 2000s. This is a registry-based study. Data were obtained from birth certificates of all live births in the city from 1994 to 2005. The variables analysed were: VLBW as the dependent variable and maternal age and schooling, type of delivery, type of hospital, number of live births, gestational age, newborn gender and unemployment rate. The incidence ratio rate (IRR) using Poisson regression was calculated to identify possible trends in VLBW rates. Poisson regressions were performed in order to assess the influence of some independent variables on VLBW. A total of 257,740 singleton newborns were delivered in the city during the period, with a steady reduction in the total number of live births per year from 23,296 in 1994 to 18,325 in 2005. The results showed a small but significant increase in VLBW (p for trend=0.049). There was a significant trend towards adequacy for gestational age per birth weight, suggesting a reduction in rates of intrauterine growth restriction (IUGR) (p<0.001). The findings showed a significant increase of 1% per year in the probability of VLBW. The main risk factors were related to VLBW mothers with low levels of schooling, public hospitals and multiparity and nulliparity. After adjustment, nulliparity remained as a significant risk factor. The interaction between type of hospital and type of delivery indicated that the probability for VLBW was 3.6 times higher (p<0.001) among those born in public hospitals by Caesarean section than those born in private hospitals by vaginal delivery. The results show that southern Brazil is going through a demographic transition characterized by a significant decrease in number of live births associated with a small increase in VLBW rates, a decrease in IUGR rates and stabilization of LBW.

Associação entre via de parto e complicações maternas em hospital público da Grande São Paulo, Brasil

O estudo objetivou avaliar associação entre via de parto e complicações maternas. Realizou-se coorte retrospectiva com partos ocorridos durante o ano de 2003, em um hospital público. As complicações avaliadas foram: infecção, hemorragia, histerectomia, rotura uterina, lesão de órgão contíguo, trombose venosa profunda e embolia pulmonar. Utilizou-se a odds ratio (OR) e os testes de qui-quadrado de Pearson e de Fisher, além da regressão logística. Estabeleceu-se o nível de 0,05 como significante. Foram encontradas 15 complicações. Tomando-se o parto vaginal como referência, encontrou-se associação entre cesárea e as complicações tomadas em conjunto. Analisando-se variáveis confundidoras, encontrou-se associação das complicações com hipertensão, soropositividade para HIV, placenta prévia e descolamento prematuro de placenta. Após controle para estas quatro variáveis, manteve-se a associação entre cesárea e complicações (OR = 9,7; p = 0,04). Encontrou-se também associação entre complicações e cesárea eletiva comparada ao parto vaginal (OR = 4,7; p = 0,02), e maior proporção de complicações, no limite da significância estatística, nas cesáreas eletivas comparadas à "tentativa de parto vaginal" (OR = 3; p = 0,058). Conclui-se que a cesárea associa-se a complicações maternas, mesmo após a realização de vários ajustes.

Condições de vida e mortalidade infantil no município do Embu, São Paulo

OBJETIVO: Descrever a distribuição do coeficiente de mortalidade infantil e seus componentes no município do Embu, São Paulo, no período de 1995 a 1998, segundo os estratos de condições de vida. MÉTODOS: Estudo descritivo com análise por conglomerados,dos 135 setores censitários do município de Embu, agrupados em quatro estratos de condições de vida: estrato 1, com melhores condições de moradia, renda e escolaridade; estratos 2 e 3, intermediários; estrato 4, no qual todas as moradias eram aglomerados subnormais ou favelas. Foram calculados os coeficientes de mortalidade infantil, neonatal e pós-neonatal, a proporção entre óbitos neonatais e pós-neonatais, o risco atribuível populacional e mortalidade proporcional por causas, para os anos de 1995 a 1998, segundo os quatro estratos de condições de vida estabelecidos. RESULTADOS: O estrato 4 apresentou maiores coeficientes de mortalidade infantil e risco atribuível populacional em relação aos estratos intermediários, em todos os anos do estudo. Esse estrato apresentou, também, as menores proporções entre mortalidade neonatal e pós-neonatal. O risco atribuível populacional no estrato 4 foi maior que os demais estratos para as afecções perinatais (159,4), doenças respiratórias (271,4) e doenças infecciosas (415,6). Identificaram-se dados demográficos semelhantes em áreas próximas aos limites geograficamente constituídos pelo estudo e heterogeneidade de eventos num mesmo território. CONCLUSÕES: Identificou-se uma relação entre desigualdades sociais e mortalidade infantil, segundo os critérios de condições de vida estabelecidos para este estudo, entretanto, não houve distribuição homogênea nos quatro estratos populacionais, revelando dificuldades em utilizá-los como parâmetros para desigualdades sociais em grandes centros urbanos.

The expression of vulnerability through infant mortality in the municipality of Embu

CONTEXT AND OBJECTIVE

Infant mortality expresses a set of living, working and healthcare access conditions and opens up possibilities for adopting interventions to expand equity in healthcare. This study aimed to investigate vulnerability and the consequent differences in access to health services and occurrences of deaths among infants under one year of age in the municipality of Embu.

DESIGN AND SETTING

This was a descriptive study in the municipality of Embu.

METHODS

Primary data were collected through interviews with the families of children living in the municipality of Embu who died in the years 1996 and 1997 before reaching one year of age. Secondary data were obtained from death certificates. The variables collected related to living conditions, income, occupation, prenatal care, delivery and the healthcare provided for children. These data were compared with the results obtained from a study carried out in 1996.

RESULTS

Statistically significant differences were found with regard to income, working without a formal employment contract and access to private health plans among the families of the children who died. There were also differences in access to and quality of prenatal care, frequency of low birth weight and neonatal inter-ocurrences.

CONCLUSIONS

The employment/unemployment situation was decisive in determining the degree of family stability and vulnerability to the occurrence of infant deaths, in addition to the conditions of access to and quality of healthcare services.

[Air pollution and low birth weight in the city of Rio de Janeiro, Brazil, 2002]

The objective of this study was to evaluate the effect of air pollution on low birth weight in full term singleton newborns in the city of Rio de Janeiro, Brazil. The study adopted a cross-sectional design based on the year 2002. Data on live births were obtained from the Live Birth Information System of the Brazilian Ministry of Health. Low birth weight was defined as less than 2,500 g. Maternal exposure to air pollution was defined as the mean for a given pollutant over each trimester of pregnancy and was assessed taking birth date into account. Adjusted odds ratios (OR) were estimated for each potential risk factor. For PM(10), CO, and NO(2), no significant increases were detected. For SO(2), the OR of the fourth interquartile range of exposure in the third trimester of pregnancy was 1.149 (95%CI: 1.016-1.301). For O(3), the estimated OR was 0.830 (95%CI: 0.750-0.987). When exposure variable was regarded as a continuous measure, the OR for PM(10), CO, and SO2 in the third trimester were not statistically significant and were 1.089, 2.223, and 1.259, respectively.

Determinantes do baixo peso ao nascer a partir das Declarações de Nascidos Vivos

Este estudo teve como objetivos conhecer a distribuição do peso de nascimento das crianças de Campinas (SP) e indicar fatores de risco para baixo peso. Realizou-se estudo transversal no qual foram utilizados dados das 14.444 Declarações de Nascidos Vivos de 2001. A variável dependente foi o peso de nascimento, e as independentes as características maternas, gestacionais, do parto e do recém-nascido. Na avaliação da associação entre variáveis empregou-se teste de qui-quadrado e calculou-se valores de odds ratio brutos (OR) e ajustados (ORaj). A média do peso de nascimento foi 3.142g, variando de 285 a 5.890g; 65,1% das crianças pesaram 3.000g ou mais, 25,7% entre 2.500 e 2.999g e 9,1% menos de 2.500g. Os determinantes para baixo peso em prematuros foram cesariana, gemelaridade, recém-nascidos femininos e os de mulheres com menos de sete consultas de pré-natal. Para crianças a termo os riscos foram gestação dupla, tripla ou mais, filhos de mulheres com mais de 34 anos, das com até sete anos de estudo, com oito a onze e das com menos de sete consultas de pré-natal. A distribuição de peso de nascimento em Campinas foi inadequada e a proporção de baixo peso foi mais que o dobro dos países desenvolvidos. Os recém-nascidos prematuros que nasceram por cesariana, os prematuros e os a termo de gestação múltipla, os femininos, os de mulheres com pré-natal inadequado e os a termo daquelas com maior idade e baixa escolaridade apresentaram maior chance de nascer com baixo peso.

Could elective cesarean sections influence the birth weight of full-term infants?

CONTEXT AND OBJECTIVE

There are no studies on birth weights among full-term infants born by means of elective cesarean section. We aimed to study this in private and public hospitals.

DESIGN AND SETTING

Retrospective study at Universidade Federal do Triângulo Mineiro, Uberaba, Brazil.

METHODS

Data were collected from the municipal medical birth register of Uberaba from January to December 2000. The data obtained (maternal age, type of delivery, number of prenatal care visits and birth weight, from full-term pregnancy) from the university hospital (UH), which is a tertiary hospital that only attends patients within the National Health System (SUS), were compared with data from four private hospitals (PHs) that attend health insurance plans and private patients. Student's t test, chi2 test and multiple logistic regression were used for statistical analysis, with the significance level set at p < 0.05.

RESULTS

In the PHs, 1,100 out of 1,354 births (81.2%) were by cesarean section and in the UH, 373 out of 1,332 (28%). Birth weight increased significantly in association with increasing numbers of prenatal care visits, except for cesarean section cases in PHs. Birth weights among vaginal delivery cases in PHs were greater than in the UH (p < 0.05), but this was not observed among cesarean section cases. Multiple logistic regression showed that there was greater risk of low birth weight in PHs (odds ratio: 2.33; 95% confidence interval: 1.19 to 4.55).

CONCLUSION

Elective cesarean section performed in PHs may be associated with low birth weight among full-term infants.

Características das mães adolescentes e de seus recém-nascidos e fatores de risco para a gravidez na adolescência em Campinas, SP, Brasil

OBJETIVOS: descrever o perfil das mães e seus recém-nascidos e apontar fatores de risco para gravidez na adolescência. MÉTODOS: estudo transversal que analisou os nascimentos de filhos de adolescentes ocorridos em Campinas, SP, Brasil em 2001. Identificou-se o perfil pelas características sociodemográficas maternas, relacionadas às gestações, aos partos e recém-nascidos. Realizou-se teste de qui-quadrado e calcularam-se os odds ratio (OR) brutos. Para os OR ajustados, empregou-se modelo de regressão logística. RESULTADOS: as adolescentes eram 17,8% das mães. Dessas, 48,4% tinham até sete anos de estudo, 59,9% não tinham companheiro, 87,6% não trabalhavam, 46,0% viviam em regiões com baixas condições de vida; a maioria era primípara, 21,6% tinham um filho ou mais, 35,2% fizeram menos que sete consultas no pré-natal. Dos recém-nascidos, 7,5% nasceram prematuros, 36,2% por cesárea, 9,7% com baixo peso e 30,3% com peso insuficiente. Encontraram-se associações entre gravidez na adolescência e mulheres sem companheiro (ORaj=2,63; IC95%=2,35-2,94), sem ocupação (ORaj=3,29; IC95%=2,85-3,79), de regiões com baixas condições de vida (Noroeste [ORaj=1,30; IC95%=1,07-1,59] e Sudoeste [ORaj=1,22; IC95%=1,01-1,47]) e com pré-natal inadequado (ORaj=1,22; IC95%=1,09-1,38). CONCLUSÕES: o perfil das mães adolescentes e dos seus partos e os fatores de risco para gravidez na adolescência relacionaram-se principalmente com condições socioeconômicas desfavoráveis, sugerindo que as intervenções requerem ações intersetoriais.

Infant mortality: comparison between two birth cohorts from Southeast and Northeast, Brazil

OBJECTIVE: To obtain population estimates and profile risk factors for infant mortality in two birth cohorts and compare them among cities of different regions in Brazil. METHODS: In Ribeirão Preto, southeast Brazil, infant mortality was determined in a third of hospital live births (2,846 singleton deliveries) in 1994. In São Luís, northeast Brazil, data were obtained using systematic sampling of births stratified by maternity unit (2,443 singleton deliveries) in 1997-1998. Mothers answered standardized questionnaires shortly after delivery and information on infant deaths was retrieved from hospitals, registries and the States Health Secretarys' Office. The relative risk (RR) was estimated by Poisson regression. RESULTS: In São Luís, the infant mortality rate was 26.6/1,000 live births, the neonatal mortality rate was 18.4/1,000 and the post-neonatal mortality rate was 8.2/1,000, all higher than those observed in Ribeirão Preto (16.9, 10.9 and 6.0 per 1,000, respectively). Adjusted analysis revealed that previous stillbirths (RR=3.67 vs 4.13) and maternal age <18 years (RR=2.62 vs 2.59) were risk factors for infant mortality in the two cities. Inadequate prenatal care (RR=2.00) and male sex (RR=1.79) were risk factors in São Luís only, and a dwelling with 5 or more residents was a protective factor (RR=0.53). In Ribeirão Preto, maternal smoking was associated with infant mortality (RR=2.64). CONCLUSIONS: In addition to socioeconomic inequalities, differences in access to and quality of medical care between cities had an impact on infant mortality rates.

Efeito moderador do risco social na relação entre risco biológico e desempenho funcional infantil

OBJETIVOS: avaliar impacto da interação nascimento pré-termo e nível socioeconômico (NSE) da família no desempenho funcional e na independência em tarefas da rotina diária, em crianças de três anos de idade. MÉTODOS: estudo transversal com 40 crianças, alocadas em quatro grupos, conforme variáveis de risco biológico e de risco social alto e baixo. A habilidade e a independência das crianças foram avaliadas pelo teste funcional padronizado PEDI, nas áreas: auto-cuidado, mobilidade e função social. RESULTADOS: foram revelados fatores de interação significativos nas habilidades funcionais de mobilidade e na independência em função social. Contrastes mostraram diferenças significativas entre crianças pré-termo e a termo, de NSE baixo. Crianças nascidas pré-termo apresentaram escores inferiores nos dois aspectos de desempenho funcional. Não foram observadas diferenças significativas nos grupos de crianças de NSE alto, nas áreas avaliadas. CONCLUSÕES: o risco social (fator moderador) modificou a relação entre risco biológico e habilidades de mobilidade e independência em função social. A interação entre fatores biológicos e sociais, e não apenas a presença de único fator de risco, influencia o desempenho funcional aos três anos de idade. Os resultados ampliam ações terapêuticas para crianças expostas a fatores de risco biológico e social.

Association between ambient air pollution and birth weight in São Paulo, Brazil

OBJECTIVES

Previous studies have implicated air pollution in increased mortality and morbidity, especially in the elderly population and children. More recently, associations with mortality in infants and with some reproductive outcomes have also been reported. The aim of this study is to explore the association between exposure to outdoor air pollution during pregnancy and birth weight.

DESIGN

Cross sectional study using data on all singleton full term live births during a one year period. For each individual birth, information on gestational age, type of delivery, birth weight, sex, maternal education, maternal age, place of residence, and parity was available. Daily mean levels of PM(10), sulphur dioxide, nitrogen dioxide, carbon monoxide, and ozone were also gathered. The association between birth weight and air pollution was assessed in regression models with exposure averaged over each trimester of pregnancy.

SETTING

São Paulo city, Brazil.

RESULTS

Birth weight was shown to be associated with length of gestation, maternal age and instruction, infant gender, number of antenatal care visits, parity, and type of delivery. On adjusting for these variables negative effects of exposure to PM(10) and carbon monoxide during the first trimester were observed. This effect seemed to be more robust for carbon monoxide. For a 1 ppm increase in mean exposure to carbon monoxide during the first trimester a reduction of 23 g in birth weight was estimated.

CONCLUSIONS

The results are consistent in revealing that exposure to air pollution during pregnancy may interfere with weight gain in the fetus. Given the poorer outlook for low birthweight babies on a number of health outcomes, this finding is important from the public health perspective.

[Prenatal and childbirth care equity in an area in Greater Metropolitan São Paulo, 1996]

A cross-sectional study was conducted to evaluate prenatal and childbirth care interviewing mothers of infants in the municipality of Embu (Greater Metropolitan São Paulo) in 1996, according to four socioeconomic strata. A door-to-door survey included a probabilistic sample consisting of 483 infants. In all strata more than 90% of the mothers had received prenatal care, but with late access in stratum 4 (residents of favelas, or slums). Breast examination during prenatal care, reported by only 60.8% of the mothers, was the worst single indicator of quality of prenatal care in the municipality. The outcome indicator - first prenatal consultation after the first trimester and total number of consultations less than six - was associated with maternal age (less than 20 years), low per capita family income (less than one minimum wage), and lack of private health plan. As for deliveries, 97.7% occurred in hospital, of which 32.5% by cesarean section, with the latter more frequent in private health care facilities (63.2%). No population segments were identified as being excluded from the health care system, but some indicators suggest greater deficiencies in socioeconomic stratum 4. These results have supported local health system managers in redefining health measures for the municipality.

Mortalidade neonatal no Município de São Paulo: influência do peso ao nascer e de fatores sócio-demográficos e assistenciais

INTRODUÇÃO: A mortalidade neonatal no Município de São Paulo, apesar da sua tendência decrescente, constitui em um importante problema para a saúde pública. Os principais fatores de risco podem ser agrupados em quatro categorias básicas de variáveis: características do recém-nascido, características maternas, condições socioeconômicas e características dos serviços de saúde. O peso ao nascer e a prematuridade constituem fatores dominantes, compondo complexas redes de articulação com os demais. METODOLOGIA: Este é um estudo caso-controle, com base em dados vinculados do SIM e SINASC no Município de São Paulo, no primeiro semestre de 1995. Foi utilizada análise hierárquica, considerando quatro blocos de variáveis (características socioeconômicas, do recém-nascido, maternas e serviços de saúde) para o conjunto de recém-nascidos e para três grupos de peso ao nascer: <1.500g, 1.500- 2.499g e 2.500g e mais. RESULTADOS: No modelo final para o conjunto de recém-nascidos mostraram associação com óbito neonatal, a idade materna inferior a de 20 anos, nascer em hospital vinculado ao SUS, peso ao nascer <2.500g e prematuridade. Os três grupos de peso ao nascer exibiram perfis distintos de fatores de risco. Os RN <1.500g tiveram menor mortalidade quando nasceram em hospital universitário e por cesárea. Nos RN de 1.500-2.499g a mortalidade estava associada a prematuridade, sexo masculino e mãe grande multípara. No grupo com peso acima de 2.500g, os fatores de risco para mortalidade foram a prematuridade, mãe adolescente, morar em área com qualidade de vida precária e nascer por cesárea e em hospital vinculado ao SUS. CONCLUSÃO: Esse estudo, além de apontar a enorme influência do peso ao nascer sobre a mortalidade neonatal, no MSP, demonstrou que as diferentes categorias de peso apresentam vulnerabilidades biológicas e sociais distintas, que constituem articulações complexas, e que os serviços de saúde têm um importante papel a desempenhar em cada uma delas.