The challenge of reducing neonatal mortality in middle-income countries: findings from three Brazilian birth cohorts in 1982, 1993, and 2004.

BACKGROUND: Middle-income countries will need to drastically reduce neonatal deaths to achieve the Millennium Development Goal for child survival. The evolution of antenatal and perinatal care indicators in the Brazilian city of Pelotas from 1982 to 2004 provides a useful case study of potential challenges. METHODS: We prospectively studied three birth cohorts representing all urban births in 1982, 1993, and from January to July, 2004. The same methods were used in all three studies. FINDINGS: Despite improvements in maternal characteristics, prevalence of preterm births increased from 6.3% (294 of 4665) in 1982 to 16.2% (342 of 2112) in 2004, corresponding to a 47 g reduction in mean birthweight. Average number of antenatal visits in 2004 was 8.3 per woman, but quality of care was still inadequate--97% of women had an ultrasound scan, but only 1830 (77%) had a vaginal examination and 559 of 1748 non-immunised women did not receive tetanus toxoid. Rate of caesarean sections increased greatly, from 28% (1632 of 5914) in 1982 to 43% (1039 of 2403) in 2004, reaching 374 of 456 (82%) of all private deliveries in 2004. The increased rate of preterm births seemed to result largely from caesarean sections or inductions. Newborn care improved, and gestational-age-specific mortality rates had fallen by about 50% since 1982. As a result, neonatal mortality rates had been stable since 1990, despite the increase in preterm deliveries. INTERPRETATION: Excessive medicalisation--including labour induction, caesarean sections, and inaccurate ultrasound scans--led by an unregulated private sector with spill-over effects to the public sector, might offset the gains resulting from improved maternal health and newborn survival. These challenges will have to be faced by middle-income countries striving to achieve the child survival Millennium Development Goal.

Achieving universal coverage with health interventions.

Cost-effective public health interventions are not reaching developing country populations who need them. Programmes to deliver these interventions are too often patchy, low quality, inequitable, and short-lived. We review the challenges of going to scale, building on known, effective interventions to achieve universal coverage. One challenge is to choose interventions consistent with the epidemiological profile of the population. A second is to plan for context-specific delivery mechanisms effective in going to scale, and to avoid uniform approaches. A third is to develop innovative delivery mechanisms that move incrementally along the vertical-to-horizontal axis as health systems gain capacity in service delivery. The availability of sufficient funds is essential, but constraints to reaching universal coverage go well beyond financial issues. Accurate estimates of resource requirements need a full understanding of the factors that limit intervention delivery. Sound decisions need to be made about the choice of delivery mechanisms, the sequence of action, and the pace at which services can be expanded. Strong health systems are required, and the time frames and funding cycles of national and international agencies are often unrealistically short.

The multi-country evaluation of the integrated management of childhood illness strategy: lessons for the evaluation of public health interventions.

The Multi-Country Evaluation of the Integrated Management of Childhood Illness (IMCI) includes studies of the effectiveness, cost, and impact of the IMCI strategy in Bangladesh, Brazil, Peru, Tanzania, and Uganda. Seven questions were addressed when the evaluation was designed: who would be in charge, through what mechanisms IMCI could affect child health, whether the focus would be efficacy or effectiveness, what indicators would be measured, what types of inference would be made, how costs would be incorporated, and what elements would constitute the plan of analysis. We describe how these questions were answered, the challenges encountered in implementing the evaluation, and the 5 study designs. The methodological insights gained can improve future evaluations of public health programs.

The Pelotas birth cohort study, Rio Grande do Sul, Brazil, 1982-2001.

Given the growing recognition of the importance of the life course approach for the determination of chronic diseases, birth cohort studies are becoming increasingly important. This paper describes the methods used in the 1982 Pelotas (Brazil) birth cohort study, one of the largest and longest studies of this type in developing countries. All 5,914 hospital births occurring in Pelotas in 1982 (over 99% of all deliveries) were studied prospectively. The main stages of the study took place in 1983, 1984, 1986, 1995, 1997, 2000, and 2001. More than two thousand variables are available for each subject who participated in all stages of the study. Recent phases of the study included the examination of 2,250 males when presenting for the army recruitment exam in 2000, the study of a 27% sample of men and women in 2001 through household visits, and the study of over 400 children born to the cohort women. Follow-up rates in the recent stages of the cohort were 78.9% for the army examination and 69.0% for the household visits. Ethnographic and oral health studies were conducted in sub-samples. Some recent results on blood pressure, adolescent pregnancy, and asthma are presented as examples of utilization of the data. Suggestions on lessons learned for other cohort studies are proposed.

The Pelotas birth cohort study, Rio Grande do Sul, Brazil, 1982-2001

Given the growing recognition of the importance of the life course approach for the determination of chronic diseases, birth cohort studies are becoming increasingly important. This paper describes the methods used in the 1982 Pelotas (Brazil) birth cohort study, one of the largest and longest studies of this type in developing countries. All 5,914 hospital births occurring in Pelotas in 1982 (over 99 percent of all deliveries) were studied prospectively. The main stages of the study took place in 1983, 1984, 1986, 1995, 1997, 2000, and 2001. More than two thousand variables are available for each subject who participated in all stages of the study. Recent phases of the study included the examination of 2,250 males when presenting for the army recruitment exam in 2000, the study of a 27 percent sample of men and women in 2001 through household visits, and the study of over 400 children born to the cohort women. Follow-up rates in the recent stages of the cohort were 78.9 percent for the army examination and 69.0 percent for the household visits. Ethnographic and oral health studies were conducted in sub-samples. Some recent results on blood pressure, adolescent pregnancy, and asthma are presented as examples of utilization of the data. Suggestions on lessons learned for other cohort studies are proposed

The epidemiological transition in maternal and child health in a Brazilian city, 1982-93: a comparison of two population-based cohorts.

Two studies carried out in 1982 and 1993 in the city of Pelotas, Southern Brazil, provide a unique opportunity for assessing the impact on maternal and child health of the economic and health care changes, which took place in Brazil in this period. The cohorts of mothers and infants of 1982 and 1993 were studied from the time of delivery. In both years, all mothers identified in the city's maternity hospitals answered a standardised questionnaire and their infants were examined. Over 99% of all children born in the city in each of the 2 years were included in the cohorts. Deaths occurring among these children were monitored prospectively, as well as all hospital admissions in the 1993 cohort. In the 1982 study, attempts were made to locate a 25% sample of the children at the mean age of 12 months using the addresses collected at the hospital (82% of the children were located), and all of the cohort children at the mean age of 20 months and 42 months, through a city census (87% were located in both follow-ups). In the 1993 study, 20% of all children plus all low birthweight infants were sought at 12 months of age, using the addresses collected at the hospital, and 95% were successfully traced. There was a 12% fall in the number of births occurring in 1993 (5,304 births), in comparison with 1982 (6,011 births), in spite of the increase in the population of reproductive age in the city during the decade. There was a marked difference in maternal height and weight at the beginning of pregnancy, with women giving birth in 1993 being, on average, 3.4 cm taller and 2.5 kg heavier than those who gave birth in 1982. The proportion of preterm babies (<37 weeks), measured by the date of last menstrual period, increased from 5.6% in 1982 to 7.5% in 1993. The median duration of breast feeding increased from 3.1 months in 1982 to 4.0 months in 1993. At 12 months of age, the prevalence of deficit of weight for age decreased from 5.4% in 1982 to 3.7% in 1993. The prevalence of deficit of height for age, however, increased from 5.3% to 6.1%. The perinatal mortality rate dropped 31%, from 32.2 per 1,000 births in 1982 to 22.1 deaths per 1,000 births in 1993. There was also a marked reduction in the infant mortality rate, from 36.4 per 1,000 livebirths in 1982 to 21.1 per 1,000 livebirths in 1993. The findings of the study indicate that there were improvements in the decade for most of the indicators evaluated, with the exception of birthweight and gestational age. It appears that improvements in perinatal and infant mortality rates are largely due to improvements in the health care sector.

Explaining trends in inequities: evidence from Brazilian child health studies.

There is considerable international concern that child-health inequities seem to be getting worse between and within richer and poorer countries. The "inverse equity hypothesis" is proposed to explain how such health inequities may get worse, remain the same, or improve over time. We postulate that as new public-health interventions and programmes initially reach those of higher socioeconomic status and only later affect the poor, there are early increases in inequity ratios for coverage, morbidity, and mortality indicators. Inequities only improve later when the rich have achieved new minimum achievable levels for morbidity and mortality and the poor gain greater access to the interventions. The hypothesis was examined using three epidemiological data sets for time trends in child-health inequities within Brazil. Time trends for inequity ratios for morbidity and mortality, which were consistent with the hypothesis, showed both improvements and deterioration over time, despite the indicators showing absolute improvements in health status between rich and poor.

Brugia malayi microfilariae (Nematoda: Filaridae) enhance the infectivity of Venezuelan equine encephalitis virus to Aedes mosquitoes (Diptera: Culicidae).

We examined the potentially conflicting effects that microfilarial (MF) enhancement of viral infectivity and MF-induced mortality in mosquitoes have on the vectorial capacity of Aedes aegypti (L.), Aedes triseriatus (Say), and Aedes taeniorhynchus (Wiedemann) for Venezuelan equine encephalitis virus (VEE) when mosquitoes feed on gerbils co-infected with Brugia malayi (Buckley). Groups of mosquitoes were fed on gerbils that were either dually infected (VEE plus B. malayi MF) or singly infected (VEE only). Mosquito mortality was recorded daily, and 5-8 d later, surviving mosquitoes were assayed for disseminated viral infection. The contrasting effects of MF enhancement and MF-induced mortality differed among mosquito species and were determined by the nature and consequences of MF penetration through the mosquito midgut, but not to differences in mosquito susceptibilities to parenterally introduced virus. In Ae. aegypti, MF-induced mortality was high and tended to eliminate any significant effect of MF enhancement. In Ae. triseriatus, MF-induced mortality was low, and feeding on dually infected hosts resulted in 9 times as many mosquitoes with disseminated viral infections as did feeding on singly-infected hosts. In Ae. taeniorhynchus, MF-induced mortality was extremely high, yet under our experimental conditions, feeding on a dually infected hosts resulted in nearly 30 times as many disseminated infections as did feeding on singly infected hosts. The final outcome on vectorial capacity depended on the specific combination of MF, virus, and mosquito species involved. Therefore, future efforts toward understanding MF enhancement should be directed toward mosquito-virus-parasite species combinations that occur together in nature.

Epidemiologia para municípios: manual para gerenciamento dos distritos sanitários / Epidemiology for municipalities: manual for management of sanitary districts

Guia sobre epidemiologia e sua relaçäo com o planejamento, gerenciamento e avaliaçäo, enfatizando o uso de informaçöes epidemiológicas no planejamento ao nível municipal e distrital.

Land tenure and child health in Rio Grande do Sul: the relationship between agricultural production, malnutrition and mortality.

"Four different approaches were applied to test the hypothesis that patterns of land tenure and agricultural production in Rio Grande do Sul [Brazil] are important infant mortality determinants. These studies have employed various data sources on distinct analytical levels.... The results...provide reliable evidence of there being a strong relationship between the degree of concentration of land tenure and agricultural production on the one hand, and malnutrition and infant mortality on the other."

[Longitudinal study of the mother and child population in an urban region of southern Brazil, 1993: methodological aspects and preliminary results]. / Estudo longitudinal da população materno-infantil da região urbana do Sul do Brasil, 1993: aspectos metodológicos e resultados preliminares.

All babies born in the hospitals of the city of Pelotas, Brazil, in 1982 were studied soon after delivery and followed up prospectively during the first years of their lives. In 1993, this study was repeated with a similar methodology, with the aim of assessing eventual changes in the level of maternal and child health. All five maternity hospitals in the city were visited daily and the 5,304 babies born included in the study. They were weighed and measured, and their gestational age was assessed using the Dubowitz method. Their mothers were examined and interviewed regarding a large number of risk factors. The mortality of these children was studied through the surveillance of all hospitals, cemeteries and death registries, and all hospital admissions were also recorded. Two nested case-control studies were carried out to assess risk factors for mortality and hospital morbidity. A systematic sample of 655 children were examined at home at one and three months of age, and these infants, as well as another sample of 805 children including all low-birthweight babies were also examined at the ages of six and twelve months. Their psychomotor development was also assessed. Losses to follow-up were only 6.6% at twelve months. Relative to the 1982 indicators, perinatal mortality fell by about 30% and infant mortality by almost 50%. The median duration of breastfeeding increased from 3.1 to 4.0 months. On the other hand, there was little change in the prevalences of low birthweight or of length for age at twelve months. The article that refers this abstract describes the methodology of the study and forthcoming publications will present detailed results.

PIP: All babies born in the hospitals of the city of Pelotas, Brazil, in 1982 were studied soon after delivery and followed up prospectively during the first years of their lives. In 1993 this study was repeated with a similar methodology, with the aim of assessing eventual changes in the level of maternal and child health. All five maternity hospitals in the city were visited daily and the 5304 babies born included in the study. They were weighed and measured, and their gestational age was assessed using the Dubowitz method. Their mothers were examined and interviewed regarding a large number of risk factors. The mortality of these children was studied through the surveillance of all hospitals, cemeteries, and death registries, and all hospital admissions were also recorded. Two nested case-control studies were carried out to assess risk factors for mortality and hospital morbidity. A systematic sample of 655 children was examined at home at 1 and 3 months of age, and these infants, as well as another sample of 805 children including all low-birth-weight babies, were also examined at the ages of 6 and 12 months. Their psychomotor development was also assessed. Losses to follow-up were only 6.6% at 12 months. Relative to the 1982 indicators, perinatal mortality fell by about 30% and infant mortality by almost 50%. The median duration of breast feeding increased from 3.1 to 4.0 months. On the other hand, there was little change in the prevalences of low birth weight or of length for age at 12 months. The methodology of the study is described, and forthcoming publications will present detailed results. (author's modified)

Estudo longitudinal da populaçäo materno-infantil da regiäo urbana do Sul do Brasil, 1993: aspectos metodológicos e resultados preliminares / Longitudinal study of the mother and child population in an urban region of southern Brazil, 1993: methodological aspects and preliminary results

Em 1982, todos os nascimentos ocorridos na cidade de Pelotaas, RS - Brasil, foram estudados e essas crianças foram acompanhadas prospectivamente durante os primeiros anos de vida. Em 1993, repetiu-se o estudo com metodologia similar, com a finalidade de avaliar as eventuais mudanças no nível de saúde materno-infantil, ocorridas durante esses onze anos. Todas as cinco maternidades da cidade foram visitadas diariamente e os 5.304 nascimentos ocorridos foram incluídos no estudo. As crianças foram pesadas e medidas, sendo sua idade gestacional avaliada através do método de Dubowitz. As mäes foram examinadas e entrevistadas sobre um grande número de fatores de risco. A mortalidade dessas crianças foi monitorizada por visitas regulares a hospitais, cemitérios e registros de óbito, e todas as internaçöes hospitalares foram acompanhadas. Dois estudos aninhados de casos e controles foram realizados para investigar fatores de risco para mortalidade e hospitalizaçöes. Uma amostra sistemática de 655 crianças foram examinadas em casa com um e três meses de idade, e essas mesmas crianças, acrescidas de outras 805 (que incluíram todos os recém-nascidos de baixo peso) foram também acompanhadas aos seis e doze meses de idade. O desenvolvimento psicomotor dessas amostras foi também avaliado. As perdas de acompanhamento aos doze meses foram de apenas 6,6 por cento. Em relaçäo aos dados de 1982, a pesquisa de 1993 mostrou reduçäo de cerca de 30 por cento na mortalidade perinatal e de quase 50 por cento na mortalidade infantil, assim como aumento de um mês na duraçäo mediana da amamentaçäo. Por outro lado, näo houve qualquer alteraçäo nas prevalências de baixo peso ao nascer e de déficit de comprimento/idade aos doze meses. O artigo a que se refere este resumo descreve a metodologia do estudo, ao qual se segue uma série de outras publicaçöes

Tendências e diferenciais na saúde materno-infantil: delineamento e metodologia das coortes de 1982 e 1993 de mäes e crianças de Pelotas, Rio Grande do Sul / Trends and defferentials in maternal and child health: design and metodology of the 1982 and 1993 birth cohort studies in Pelotas, Rio Grande do Sul

Mudanças ocorridas na última década em termos econômicos e assistenciais podem haver afetado a saúde materno-infantil. Dois estudos foram realizados em Pelotas, Rio Grande do Sul. As coortes de mäes e recém-nascidos noa anos de 1982 e 1993 foram estudadas desde o nascimento. As mäes foram identificadas nos hospitais-maternidade e responderam a um questionário padronizado sendo seus filhos examinados. Mais de 99 por cento dos recém-nascidos foram incluídos nas coortes, totalizando 5914 nascidos vivos em 1982 e 5249 em 1993. A mortalidade das crianças foi monitorizada, e em 1993 as hospitalizaçoes também o foram. Em 1982, tentou-se localizar cerca de 25 por cento das crianças aos 12 meses de idade e todas com a idade média de vinte meses. Foi possível encontrar cerca de 82 por cento das crianças aos 12 meses e, graças a uma mudança de estratégia, 87 por cento aos vinte meses. Em 1993, tentou-se acompanhar 20 por cento das crianças e mais todos os recém-nascidos de baixo peso aos 12 meses de idade, sendo 95 por cento localizados. Descreve os principais aspectos metodológicos de ambos os estudos, cujos principais resultados estäo incluídos nos próximos artigos desse suplemento.

Early childhood mortality in a Brazilian cohort: the roles of birthweight and socioeconomic status.

The deaths of children aged 1-4 years were studied in a cohort of 5914 Brazilian liveborns. A total of 29 early childhood deaths were recorded (cumulative mortality risk of approximately 6 per 1000), 17 of which (59%) were due to infectious diseases. The death rate was highest in the second year. Deaths were highly concentrated in children from low income (< US $50/month) families, where the cumulative risk of early childhood death was about 10 per 1000; on the other hand, there were no deaths among the 616 children from families with a monthly income of US $300 or more. Birthweight was also associated with mortality: the cumulative risk of children weighing less than 2000 g at birth was 21 per 1000, compared to 4 per 1000 among those with birthweights of 3500 g or more. Simultaneous adjustment for income and birthweight did not substantially change these differentials. These findings confirm the strong association between early childhood mortality and socioeconomic conditions, but also make evident the long-term effects of low birthweight.

PIP: Mortality was studied among a cohort of 5914 Brazilian live-borns aged 1-4 years. 29 early childhood deaths were recorded, 17 of which were due to infectious diseases. The highest death rate was observed in the 2nd year. Deaths were highly concentrated among children of families with income US$50/month, with a 10/1000 cumulative risk of early childhood death. No deaths, however, occurred among the 616 children from families with monthly income or= US$300. As for birth weight, the cumulative risk of death among children weighing 2000 gm at birth was 21/1000, compared with 4/1000 among those with birth weights of 3500 gm or more. Simultaneous adjustments for both income and birth weight failed to substantially change mortality differentials. Study results therefore confirm the strong association between early childhood mortality, income, and low birth weight.

Comparison of the causes and consequences of prematurity and intrauterine growth retardation: a longitudinal study in southern Brazil.

A cohort of 5914 liveborns (99% of the city births) was followed up to the age of 4 years in Pelotas, southern Brazil. Besides the perinatal evaluation, the cohort children were examined again at mean ages of 11, 23, and 47 months. During each visit the children were weighed and measured and information on morbidity was collected. Also, multiple sources of information were used for monitoring mortality throughout the study. Of the babies with known gestational age, 9.0% were classified as intrauterine growth-retarded and 6.3% as preterm. Excluding those of unknown gestational age, 62% of low birth weight babies were intrauterine growth-retarded and 36% were preterm. Intrauterine growth retardation was statistically associated with maternal height, prepregnancy weight, birth interval, and smoking, whereas preterm births were associated with maternal prepregnancy weight and maternal age. Preterm babies had a perinatal mortality rate 13 times higher than that of babies of appropriate birth weight and gestational age and 2 times higher than that of intrauterine growth-retarded babies. Infant mortality rates presented a similar pattern, with the differentials being more pronounced during the neonatal than in the postneonatal period. In the first 2 years of life intrauterine growth-retarded children were at almost twice the risk of being hospitalized for diarrhea compared with appropriate birth weight, term children, while preterm children experienced only a slightly greater risk. For pneumonia, however, both groups of children were hospitalized significantly more than appropriate birth weight, term children. In terms of growth, despite their earlier disadvantage, preterm children gradually caught up with their appropriate birth weight, term counterparts.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth spacing and child health in urban Brazilian children.

The associations between birth interval and a range of child health outcomes were examined in a population-based cohort of approximately 3500 urban Brazilian children. The effects of several socioeconomic and maternal confounding factors were controlled for in the analyses. Children born after shorter birth intervals (less than 18 and 18 through 23 months) were disadvantaged with respect to most of the health outcomes when compared with children born after intermediate birth intervals (24 through 35, 36 through 47, and 48 through 71 months). Effects were particularly marked for birth weight, postneonatal mortality, and anthropometric status at mean age 19 months. Children born after a long birth interval (greater than 71 months) also showed some disadvantage for birth weight, perinatal mortality, and infant mortality. However, this group experienced lower risks of hospitalizations during the first 19 months of life and better anthropometric status at mean age 19 months. This study provides data that are scarce from such settings and contributes to the quantification of associations between birth spacing and child health. This information is important in the planning of appropriate intervention strategies.