Maternal and child health in Brazil: progress and challenges

In the past three decades, Brazil has undergone rapid changes in major social determinants of health and in the organisation of health services. In this report, we examine how these changes have affected indicators of maternal health, child health, and child nutrition. We use data from vital statistics, population censuses, demographic and health surveys, and published reports. In the past three decades, infant mortality rates have reduced substantially, decreasing by 5·5% a year in the 1980s and 1990s, and by 4·4% a year since 2000 to reach 20 deaths per 1000 livebirths in 2008. Neonatal deaths account for 68% of infant deaths. Stunting prevalence among children younger than 5 years decreased from 37% in 1974-75 to 7% in 2006-07. Regional differences in stunting and child mortality also decreased. Access to most maternal-health and child-health interventions increased sharply to almost universal coverage, and regional and socioeconomic inequalities in access to such interventions were notably reduced. The median duration of breastfeeding increased from 2·5 months in the 1970s to 14 months by 2006-07. Official statistics show stable maternal mortality ratios during the past 10 years, but modelled data indicate a yearly decrease of 4%, a trend which might not have been noticeable in official reports because of improvements in death registration and the increased number of investigations into deaths of women of reproductive age. The reasons behind Brazil's progress include: socioeconomic and demographic changes (economic growth, reduction in income disparities between the poorest and wealthiest populations, urbanisation, improved education of women, and decreased fertility rates), interventions outside the health sector (a conditional cash transfer programme and improvements in water and sanitation), vertical health programmes in the 1980s (promotion of breastfeeding, oral rehydration, and immunisations), creation of a tax-funded national health service in 1988 (coverage of which expanded to reach the poorest areas of the country through the Family Health Program in the mid-1990s); and implementation of many national and state-wide programmes to improve child health and child nutrition and, to a lesser extent, to promote women's health. Nevertheless, substantial challenges remain, including overmedicalisation of childbirth (nearly 50% of babies are delivered by caesarean section), maternal deaths caused by illegal abortions, and a high frequency of preterm deliveries.

Adolescent blood pressure, body mass index and skin folds: sorting out the effects of early weight and length gains

BACKGROUND

Although there is longstanding evidence of the short-term benefits of promoting rapid growth for young children in low-income settings, more recent studies suggest that early weight gain can also increase the risk of chronic diseases in adults. This paper attempts to separate the effects of early life weight and length/height gains on blood pressure, body mass index (BMI), sum of skin folds and subscapular/triceps skin fold ratio at 14-15 years of age.

METHODS

The sample comprised 833 members of a prospective population-based birth cohort from Brazil. Conditional size (weight or height) analyses were used to express the difference between observed size at a given age and expected size based on a regression, including all previous measures of the same anthropometric index. A positive conditional weight or height indicates growing faster than expected given prior size.

RESULTS

Conditional weights at all age ranges were positively associated with most outcomes; each z-score of conditional weight at 4 years was associated with an increase of 6.1 mm in the sum of skin folds (95% CI 4.5 to 7.6) in adolescence after adjustment for conditional length/height. Associations of the outcomes with conditional length/height were mostly negative or non-significant-each z-score was associated with a reduction of 2.4 mm (95% CI -3.8 to -1.1) in the sum of skin folds after adjustment for conditional weight. No associations were found with the skin fold ratio.

CONCLUSION

The promotion of rapid length/height gain without excessive weight gain seems to be beneficial for long-term outcomes, but this requires confirmation from other studies.

Infant-feeding patterns and cardiovascular risk factors in young adulthood: data from five cohorts in low- and middle-income countries

BACKGROUND

Infant-feeding patterns may influence lifelong health. This study tested the hypothesis that longer duration of breastfeeding and later introduction of complementary foods in infancy are associated with reduced adult cardiovascular risk.

METHODS

Data were pooled from 10 912 subjects in the age range of 15-41 years from five prospective birth-cohort studies in low-/middle-income countries (Brazil, Guatemala, India, Philippines and South Africa). Associations were examined between infant feeding (duration of breastfeeding and age at introduction of complementary foods) and adult blood pressure (BP), plasma glucose concentration and adiposity (skinfolds, waist circumference, percentage body fat and overweight/obesity). Analyses were adjusted for maternal socio-economic status, education, age, smoking, race and urban/rural residence and infant birth weight.

RESULTS

There were no differences in outcomes between adults who were ever breastfed compared with those who were never breastfed. Duration of breastfeeding was not associated with adult diabetes prevalence or adiposity. There were U-shaped associations between duration of breastfeeding and systolic BP and hypertension; however, these were weak and inconsistent among the cohorts. Later introduction of complementary foods was associated with lower adult adiposity. Body mass index changed by -0.19 kg/m(2) [95% confidence interval (CI) -0.37 to -0.01] and waist circumference by -0.45 cm (95% CI -0.88 to -0.02) per 3-month increase in age at introduction of complementary foods.

CONCLUSIONS

There was no evidence that longer duration of breastfeeding is protective against adult hypertension, diabetes or overweight/adiposity in these low-/middle-income populations. Further research is required to determine whether 'exclusive' breastfeeding may be protective. Delaying complementary foods until 6 months, as recommended by the World Health Organization, may reduce the risk of adult overweight/adiposity, but the effect is likely to be small.

Conceptual issues related to the construction of prescriptive standards for the evaluation of postnatal growth of preterm infants

Monitoring and interpreting the growth of preterm infants is a major clinical task for neonatologists. The effectiveness of this process depends upon the robustness of the standard selected. Concerns have been raised regarding the nature of the charts currently being used, as well as their appropriateness for present-day neonatal care. To overcome these problems, there is a need for new prescriptive standards based on a population of preterm infants without evidence of impaired fetal growth and born to low-risk women followed up since early pregnancy for precise gestational age dating. Preterm infants contributing to the new standards should be free of congenital malformations and major clinical conditions associated with impaired postnatal growth. These infants should receive standardised, evidence-based clinical care and should follow current feeding recommendations based on exclusive/predominant breastfeeding. This strategy should provide a population that is conceptually as close as possible to the prescriptive approach used for the construction of the WHO infant and child growth standards. New international standards constructed in this way should contribute to the evidence-based care of these preterm infants.

Hospital admissions from birth to early adolescence and early-life risk factors: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study

The aim of this prospective analysis was to describe the cumulative incidence of hospital admissions in the first year of life and between 1 and 11 years of age and to explore associated factors. Hospital admissions were collected through regular monitoring in the first year of life, and through maternal report on admissions between 1 and 11 years. Analyses were stratified by sex and adjusted for confounding factors. 18.1% of children were hospitalized in the first year of life, and 30.7% between ages 1 and 11 years. Among boys, hospital admission in the first year was associated with low family income, paternal smoking during pregnancy, preterm delivery, and low birthweight. Among girls, in addition to the variables described for boys, black/mixed skin color was also a risk factor for hospital admission. For admissions between 1 and 11 years of age, low family income and gestational age > 37 weeks were found to be significant risk factors.

Concurrent determinants of blood pressure among adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study

The aim of this study was to evaluate concurrent risk factors for high blood pressure in adolescents. This is a prospective cohort study including 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. Blood pressure was measured before and after the interview, and the mean value was used in the analyses. Mean systolic blood pressure was 101.9mmHg (SD = 12.3) and mean diastolic pressure was 63.4mmHg (SD = 9.9). Adolescents with black skin had higher blood pressure than those with white skin. Mean systolic pressure among subjects in the top quartile of body mass index (BMI) was 11.6mmHg higher than among those in the lowest quartile. Mean systolic pressure among postmenarcheal girls was 5.4mmHg higher than among premenarcheal girls. Similar trends were found for diastolic arterial pressure. Our findings suggest that blood pressure control must begin already in childhood and adolescence.

Early determinants of attention and hyperactivity problems in adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study

The aim of this study was to assess early determinants of attention and hyperactivity problems in adolescents. In 1993, all hospital births in the city of Pelotas, Rio Grande do Sul State, Brazil, were monitored and mothers were interviewed (N = 5,249). At 11 years of age, 4,423 mothers answered the Strengths and Difficulties Questionnaire (SDQ) in order to evaluate attention and hyperactivity problems in the adolescents. Crude and adjusted prevalence ratios were calculated using Poisson regression. Prevalence of attention and hyperactivity problems was 19.9%. Factors associated with the outcome in the adjusted analysis were: male gender, low family income, smoking during pregnancy, minor psychiatric disorders in the mother, and history of child's behavioral/emotional problems at four years of age. Early life events impacted attention and hyperactivity problems in adolescence. Risk factors for attention and hyperactivity problems found in this study were similar to those reported in other cultures.

Caesarean sections and risk of wheezing in childhood and adolescence: data from two birth cohort studies in Brazil

Background

There is evidence from two meta-analyses that children born through caesarean section (C-section) may have an increased risk of developing asthma compared with those born through vaginal delivery.

Objective

To evaluate the association between mode of delivery and wheezing (current and persistent) in childhood and adolescence, in two birth cohort studies in Brazil.

Methods

The outcome variable was based on the International Study of Allergy and Asthma questionnaire, which collects information about wheezing within the 12 months before the interview. Persistent wheezing was defined when it was present in more than one follow-up at different ages, in the 1993 cohort. The questions were asked to mothers when children were aged 4 years (1993 and 2004 cohorts) and directly to cohort participants at 11 and 15 years (1993 cohort). Mode of delivery was collected by the research team of each cohort when children were born.

Results

Response rates in the last follow-up visit of the 1993 and 2004 cohorts were 85% and 92%, respectively. The prevalence of current wheezing increased from 20% to 28% at 4 years from 1993 to 2004; at 11 and 15 years, the prevalence was around 14% and 12%, in the 1993 cohort. The proportion of C-sections increased from 30.5% to 45% between 1993 and 2004. In each cohort, the prevalence of current wheezing was similar among children born through vaginal and C-section. The risk for persistent wheezing in the 1993 cohort was higher among girls born through C-section than boys.

Conclusion

Despite the increase in the proportion of C-section in two cohorts in Southern Brazil, we found no evidence of an association between mode of delivery and the subsequent risk of wheezing. Among girls, although there was no statistical significance, the risk was higher for those born by C-section, especially regarding persistent wheezing.

Recent trends in maternal, newborn, and child health in Brazil: progress toward Millennium Development Goals 4 and 5

We analyzed Brazil's efforts in reducing child mortality, improving maternal and child health, and reducing socioeconomic and regional inequalities from 1990 through 2007. We compiled and reanalyzed data from several sources, including vital statistics and population-based surveys. We also explored the roles of broad socioeconomic and demographic changes and the introduction of health sector and other reform measures in explaining the improvements observed. Our findings provide compelling evidence that proactive measures to reduce health disparities accompanied by socioeconomic progress can result in measurable improvements in the health of children and mothers in a relatively short interval. Our analysis of Brazil's successes and remaining challenges to reach and surpass Millennium Development Goals 4 and 5 can provide important lessons for other low- and middle-income countries.

Socioeconomic inequities in the health and nutrition of children in low/middle income countries

OBJECTIVE

To describe the effects of social inequities on the health and nutrition of children in low and middle income countries.

METHODS

We reviewed existing data on socioeconomic disparities within-countries relative to the use of services, nutritional status, morbidity, and mortality. A conceptual framework including five major hierarchical categories affecting inequities was adopted: socioeconomic context and position, differential exposure, differential vulnerability, differential health outcomes, and differential consequences. The search of the PubMed database since 1990 identified 244 articles related to the theme. Results were also analyzed from almost 100 recent national surveys, including Demographic Health Surveys and the UNICEF Multiple Indicator Cluster Surveys.

RESULTS

Children from poor families are more likely, relative to those from better-off families, to be exposed to pathogenic agents; once they are exposed, they are more likely to become ill because of their lower resistance and lower coverage with preventive interventions. Once they become ill, they are less likely to have access to health services and the quality of these services is likely to be lower, with less access to life-saving treatments. As a consequence, children from poor family have higher mortality rates and are more likely to be undernourished.

CONCLUSIONS

Except for child obesity and inadequate breastfeeding practices, all the other adverse conditions analyzed were more prevalent in children from less well-off families. Careful documentation of the multiple levels of determination of socioeconomic inequities in child health is essential for understanding the nature of this problem and for establishing interventions that can reduce these differences.

Assessment of the profile of births and deaths in a referral hospital

OBJECTIVE

To compare perinatal health indicators in a referral hospital in Belo Horizonte, Brazil.

METHODS

Perinatal results and indicators of single live births in Hospital das Clínicas of Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil, were compared for two periods, 1995-1998 and 2003-2006. The chi-square test and Student's t test were applied with 5% significance level and 95% confidence interval. Data were obtained from the Perinatal Information System (Sistema Informático Perinatal, SIP), Latin American Center for Perinatology (Centro Latinoamericano de Perinatología, CLAP), Pan American Health Organization (PAHO), Hospital das Clínicas, and from medical records.

RESULTS

Mothers were approximately 26 years old on average. The number of prenatal appointments had an average increase of one appointment, regardless of birth weight, and there was a significant decrease in the number of caesarean deliveries in the second period. The average gestational age was 38 weeks in both periods, with a high rate of premature births (17.0 and 16.7%, respectively). The rate of newborns < 2,500 g was high in both periods (17.6 and 16.6%, respectively) with a decrease in the rate of newborns considered small for their gestational age. When congenital malformations were excluded, early neonatal mortality risk decreased from 12.4 per 1,000 live births in the first period to 8.0 per 1,000 live births in the second period, with considerable decrease for newborns with gestational age < 34 weeks.

CONCLUSIONS

Important differences were verified concerning health care assistance procedures and perinatal results, and they are compatible with the global improvement in neonatal health observed in the 2003-2006 period. However, the persistence of unfortunate neonatal incidents that can be reduced with the use of available perinatal technologies reveals the need for constant monitoring of perinatal hospital care for all groups of newborns.

Natural history of suspected developmental delay between 12 and 24 months of age in the 2004 Pelotas birth cohort

AIMS

To describe the incidence and persistence of suspected developmental delay (SDD) between 12 and 24 months of age and associated factors in the 2004 Pelotas Birth Cohort.

METHODS

A cohort of 4262 newborns, 3907 of whose were monitored from 12 to 24 months of life. SDD was established by Battelle Screening Developmental Inventory. The adjusted analyses were carried out using Poisson regression. Relative risks and 95% confidence intervals were calculated.

RESULTS

Incidence of SDD between 12 and 24 months of age was 1.8% (95% CI: 1.4-2.3). After the adjusted analyses, the following factors increased the risk of the incidence: Apgar 5'<7, preterm delivery, low socio-economic level, intergestational interval<or=24 months, not having been told stories in the previous 2 weeks, lack of children's books at home and male gender. A total of 390 children were positive in the 12 month (prevalence of 10%; 95% CI: 9.0-10.9). From these children, 58 remained positive up to 2 years of age, with a persistence rate of 15.6% (95% CI: 11.9-19.3). The following were factors for persistence in SDD: Apgar 5'<7, low socio-economic level, intergestational interval<or=24 months, breastfeeding duration<6 months and not having been told stories in the previous 2 weeks.

CONCLUSIONS

Easy access to children's literature and telling stories to children are inexpensive measures that may have an impact on the child's development between 12 and 24 months of life.

Risk factors for suspected developmental delay at age 2 years in a Brazilian birth cohort

Many children are at risk of not achieving their full potential for development. Epidemiological studies have the advantage of being able to identify a number of associated factors potentially amenable to intervention. Our purpose was to identify risk factors for suspected developmental delay (SDD) at age 2 years among all children born in the city of Pelotas, Brazil, in 2004. This study was part of the 2004 Pelotas Birth Cohort. The Battelle Screening Developmental Inventory (BSDI) was administered to cohort children at age 2 years. A hierarchical model of determination for SDD with confounder adjustment was built including maternal sociodemographic, reproductive and gestational characteristics, as well as child and environmental characteristics. Multivariable analysis was carried out using Poisson regression. Prevalence ratios (PR) and 95% confidence intervals [95% CI] were calculated. In the results, 3.3% of the 3869 children studied screened positive for SDD. After confounder control, children more likely to show SDD were: those with positive BSDI at age 12 months (PR = 5.51 [3.59, 8.47]); with 5-min Apgar <7 (PR = 3.52 [1.70, 7.27]); with mothers who had <4 years of schooling (PR = 3.35 [1.98, 5.66]); from social classes D and E (PR = 3.00 [1.45, 6.19]); with a history of gestational diabetes (PR = 2.77 [1.34, 5.75]); born <24 months after the last sibling (PR = 2.46 [1.42, 4.27]); were not told child stories in the preceding week (PR 2.28 [1.43, 3.63]); did not have children's literature at home (PR = 2.08 [1.27, 3.39]); with low birthweight (PR = 1.75 [1.00, 3.07]); were born preterm (PR = 1.74 [1.07, 2.81]); with <6 antenatal care appointments (PR = 1.70 [1.07, 2.68]); with history of hospitalisation (PR = 1.65 [1.09, 2.50]); and of male sex (PR = 1.43 [1.00, 2.04]). These risk factors may constitute potential targets for intervention by public policies and may provide help to paediatricians in preventing developmental delay.

'Kangaroo mother care' to prevent neonatal deaths due to preterm birth complications

Background ‘Kangaroo mother care’ (KMC) includes thermal care through continuous skin-to-skin contact, support for exclusive breastfeeding or other appropriate feeding, and early recognition/response to illness. Whilst increasingly accepted in both high- and low-income countries, a Cochrane review (2003) did not find evidence of KMC’s mortality benefit, and did not report neonatal-specific data.

Objectives The objectives of this study were to review the evidence, and estimate the effect of KMC on neonatal mortality due to complications of preterm birth.

Methods We conducted systematic reviews. Standardized abstraction tables were used and study quality assessed by adapted GRADE methodology. Meta-analyses were undertaken.

Results We identified 15 studies reporting mortality and/or morbidity outcomes including nine randomized controlled trials (RCTs) and six observational studies all from low- or middle-income settings. Except one, all were hospital-based and included only babies of birth-weight <2000 g (assumed preterm). The one community-based trial had missing birthweight data, as well as other limitations and was excluded. Neonatal-specific data were supplied by two authors. Meta-analysis of three RCTs commencing KMC in the first week of life showed a significant reduction in neonatal mortality [relative risk (RR) 0.49, 95% confidence interval (CI) 0.29–0.82] compared with standard care. A meta-analysis of three observational studies also suggested significant mortality benefit (RR 0.68, 95% CI 0.58–0.79). Five RCTs suggested significant reductions in serious morbidity for babies <2000 g (RR 0.34, 95% CI 0.17–0.65).

Conclusion This is the first published meta-analysis showing that KMC substantially reduces neonatal mortality amongst preterm babies (birth weight <2000 g) in hospital, and is highly effective in reducing severe morbidity, particularly from infection. However, KMC remains unavailable at-scale in most low-income countries.

Global report on preterm birth and stillbirth (3 of 7): evidence for effectiveness of interventions

INTRODUCTION

Interventions directed toward mothers before and during pregnancy and childbirth may help reduce preterm births and stillbirths. Survival of preterm newborns may also be improved with interventions given during these times or soon after birth. This comprehensive review assesses existing interventions for low- and middle-income countries (LMICs).

METHODS

Approximately 2,000 intervention studies were systematically evaluated through December 31, 2008. They addressed preterm birth or low birth weight; stillbirth or perinatal mortality; and management of preterm newborns. Out of 82 identified interventions, 49 were relevant to LMICs and had reasonable amounts of evidence, and therefore selected for in-depth reviews. Each was classified and assessed by the quality of available evidence and its potential to treat or prevent preterm birth and stillbirth. Impacts on other maternal, fetal, newborn or child health outcomes were also considered. Assessments were based on an adaptation of the Grades of Recommendation Assessment, Development and Evaluation criteria.

RESULTS

Most interventions require additional research to improve the quality of evidence. Others had little evidence of benefit and should be discontinued. The following are supported by moderate- to high-quality evidence and strongly recommended for LMICs: Two interventions prevent preterm births--smoking cessation and progesterone. Eight interventions prevent stillbirths--balanced protein energy supplementation, screening and treatment of syphilis, intermittant presumptive treatment for malaria during pregnancy, insecticide-treated mosquito nets, birth preparedness, emergency obstetric care, cesarean section for breech presentation, and elective induction for post-term delivery. Eleven interventions improve survival of preterm newborns--prophylactic steroids in preterm labor, antibiotics for PROM, vitamin K supplementation at delivery, case management of neonatal sepsis and pneumonia, delayed cord clamping, room air (vs. 100% oxygen) for resuscitation, hospital-based kangaroo mother care, early breastfeeding, thermal care, and surfactant therapy and application of continued distending pressure to the lungs for respiratory distress syndrome

CONCLUSION

The research paradigm for discovery science and intervention development must be balanced to address prevention as well as improve morbidity and mortality in all settings. This review also reveals significant gaps in current knowledge of interventions spanning the continuum of maternal and fetal outcomes, and the critical need to generate further high-quality evidence for promising interventions.

Weight gain in the first two years of life is an important predictor of schooling outcomes in pooled analyses from five birth cohorts from low- and middle-income countries

Schooling predicts better reproductive outcomes, better long-term health, and increased lifetime earnings. We used data from 5 cohorts (Brazil, Guatemala, India, the Philippines, and South Africa) to explore the relative importance of birthweight and postnatal weight gain for schooling in pooled analyses (n = 7945) that used appropriate statistical methods [conditional weight (CW) gain measures that are uncorrelated with prior weights] and controlled for confounding. One SD increase in birthweight, approximately 0.5 kg, was associated with 0.21 y more schooling and 8% decreased risk of grade failure. One SD increase in CW gain between 0 and 2 y, approximately 0.7 kg, was associated with higher estimates, 0.43 y more schooling, and 12% decreased risk of failure. One SD increase of CW gain between 2 and 4 y, approximately 0.9 kg, was associated with only 0.07 y more schooling but not with failure. Also, in children born in the lowest tertile of birthweight, 1 SD increase of CW between 0 and 2 y was associated with 0.52 y more schooling compared with 0.30 y in those in the upper tertile. Relationships with age at school entry were inconsistent. In conclusion, weight gain during the first 2 y of life had the strongest associations with schooling followed by birthweight; weight gain between 2 and 4 y had little relationship to schooling. Catch-up growth in smaller babies benefited schooling. Nutrition interventions aimed at women and children under 2 y are among the key strategies for achieving the millennium development goal of universal primary education by 2015.

Socio-economic and ethnic group inequities in antenatal care quality in the public and private sector in Brazil

BACKGROUND

Socio-economic inequalities in maternal and child health are ubiquitous, but limited information is available on how much the quality of care varies according to wealth or ethnicity in low- and middle-income countries. Also, little information exists on quality differences between public and private providers.

METHODS

Quality of care for women giving birth in 2004 in Pelotas, Brazil, was assessed by measuring how many of 11 procedures recommended by the Ministry of Health were performed. Information on family income, self-assessed skin colour, parity and type of provider were collected.

RESULTS

Antenatal care was used by 98% of the 4244 women studied (mean number of visits 8.3), but the number of consultations was higher among better-off and white women, who were also more likely to start antenatal care in the first trimester. The quality of antenatal care score ranged from 0 to 11, with an overall mean of 8.3 (SD 1.7). Mean scores were 8.9 (SD 1.5) in the wealthiest and 7.9 (SD 1.8) in the poorest quintiles (P < 0.001), 8.4 (SD 1.6) in white and 8.1 (SD 1.9) in black women (P < 0.001). Adjusted analyses showed that these differences seemed to be due to attendance patterns rather than discrimination. Mean quality scores were higher in the private 9.3 (SD 1.3) than in the public sector 8.1 (SD 1.6) (P < 0.001); these differences were not explained by maternal characteristics or by attendance patterns.

CONCLUSIONS

Special efforts must be made to improve quality of care in the public sector. Poor and black women should be actively encouraged to start antenatal care early in pregnancy so that they can fully benefit from it. There is a need for regular monitoring of antenatal attendances and quality of care with an equity lens, in order to assess how different social groups are benefiting from progress in health care.

Determinants of preterm birth: Pelotas, Rio Grande do Sul State, Brazil, 2004 birth cohort

Prematurity is a leading cause of neonatal mortality and a global health problem that affects high, middle and low-income countries. Several factors may increase the risk of preterm birth. In this article, we test the hypothesis that different risk factors determine preterm birth in different income groups by investigating whether risk factors for preterm deliveries in the 2004 Pelotas (Rio Grande do Sul State, Brazil) birth cohort vary among those groups. A total of 4,142 women were included in the analysis. Preterm births were equally common among women who had spontaneous vaginal deliveries as for those with induced or operative births. In the multivariate analysis the factors that remained significantly associated with preterm birth were black skin color, low education, poverty, young maternal age, primiparity, previous preterm birth, inadequacy of prenatal care and reported hypertension. In the analyses repeated after stratification by family income terciles, there was no evidence of effect modification by income and no clear difference between the socioeconomic groups. No association between cesarean section and preterm delivery was found. Further studies are required to understand the causes of the epidemic of preterm births in Brazil.

Late preterm birth is a risk factor for growth faltering in early childhood: a cohort study

BACKGROUND

Rates of preterm birth are increasing worldwide and this increase is mostly due to infants born between 34 and 36 weeks of gestational age, the so-called "late preterm" births. The aim of this study was to assess the effect of late preterm birth over growth outcomes, assessed when children were 12 and 24 months old.

METHODS

In 2004, all births taking place in Pelotas (Southern Brazil) were recruited for a cohort study. Late preterm (34/0-36/6 weeks of gestational age) and term children (37/0-42/6 weeks) were compared in terms of weight-for-age, length-for-age and weight-for-length z-scores. Weight-for-age, length-for-age and weight-for-length z-scores below -2 were considered, respectively, underweight, stunting and wasting. Singleton newborns with adequate weight for gestational age at birth, successfully followed-up either at 12 or 24 months of age were analyzed and adjusted odds ratios with 95% confidence intervals calculated through logistic regression.

RESULTS

3285 births were included, 371 of whom were late preterm births (11.3%). At 12 months, prevalence of underweight, stunting and wasting were, respectively, 3.4, 8.7 and 1.1% among late preterm children, against 1.0, 3.4 and 0.3% among term children. At 24 months, correspondent values were 3.0, 7.2 and 0.8% against 0.8, 2.9 and 0.4%. Comparing with the term children, adjusted odds of being underweighted among late preterm children was 2.57 times higher (1.27; 5.23) at 12 months and 3.36 times higher (1.56; 7.23) at 24; of being stunted, 2.35 (1.49; 3.70) and 2.30 (1.40; 3.77); and of being wasted, 3.98 (1.07; 14.85) and 1.87 (0.50; 7.01). Weight gain from birth to 12 and 24 months was similar in late preterm and term children, whereas length gain was higher in the former group in both periods.

CONCLUSION

Late preterm children grow faster than children born at term, but they are at increased risk of underweight and stunting in the first two years of life. Failure to thrive in the first two years may put them at increased risk of future occurrences of serious morbidity in late childhood and of chronic disease development in adult life.

Inequities in maternal postnatal visits among public and private patients: 2004 Pelotas cohort study

Background

The postnatal period is the ideal time to deliver interventions to improve the health of both the newborn and the mother. However, postnatal care shows low-level coverage in a large number of countries. The objectives of this study were to: 1) investigate inequities in maternal postnatal visits, 2) examine differences in postnatal care coverage between public and private providers and 3) explore the relationship between the absence of maternal postnatal visits and exclusive breastfeeding, use of contraceptive methods and maternal smoking three months after birth.

Methods

In the calendar year of 2004 a birth cohort study was started in the city of Pelotas, Brazil. Mothers were interviewed soon after delivery and at three months after birth. The absence of postnatal visits was defined as having no consultations between the time of hospital discharge and the third month post-partum. Logistic regression analysis was used to estimate the association between absence of postnatal visits and type of insurance scheme adjusting for potential confounding factors.

Results

Poorer women, black/mixed, those with lower level of education, single mothers, adolescents, multiparae, smokers, women who delivered vaginally and those who were not assisted by a physician were less likely to attend postnatal care. Postnatal visits were also less frequent among women who relied in the public sector than among private patients (72.4% vs 96% among public and private patients, respectively, x² p < 0.001) and this difference was not explained either by maternal characteristics or by health care utilization patterns. Women who attended postnatal visits were more likely to exclusively breastfeed their infants, to use contraceptive methods and to be non-smokers three months after birth.

Conclusion

Postpartum care is available for every woman free of charge in the Brazilian Publicly-funded health care system. However, low levels of postpartum care were seen in the study (77%). Efforts should be made to increase the percentage of women receiving postpartum care, particularly those in socially disadvantaged groups. This could include locally-adapted health education interventions that address women's beliefs and attitudes towards postpartum care. There is a need to monitor postpartum care and collected data should be used to guide policies for health care systems.

[Maternity and paternity in the Pelotas birth cohort from 1982 to 2004-5, Southern Brazil]

OBJECTIVE

To describe the prevalence of maternity and paternity among subjects and its association with perinatal, socioeconomic and demographic variables.

METHODS

The participants were youth, aged 23, on the average, accompanied in a cohort study since they were born, in 1982, in Pelotas (Southern Brazil) and interviewed in 2004-5. Those who were considered eligible referred having had one or more children, whether these were liveborns or stillborns. Data was collected on reproductive health as well as socioeconomic and demographic information, by means of two different instruments. The independent variables were sex and skin color, family income in 1982 and in 2004-5, changes in income, birth weight and educational level when aged 23 years old. Crude and adjusted analysis were conducted by means of Poisson regression so as to investigate the effects of the independent variables on maternity/paternity during adolescence.

RESULTS

Among the 4,297 youth interviewed, 1,373 (32%) were parents and 842 (19.6%) of these had experienced maternity/paternity during their adolescence. Planned pregnancy of the first child was directly related to the youth's age. Socioeconomic variables were inversely related to the occurrence of maternity/paternity during adolescence. The probability of being an adolescent mother was higher among black and mixed skin colored women, but skin color was not associated to adolescent paternity.

CONCLUSIONS

There was a strong relation between adolescent maternity/paternity and socioeconomic conditions, which should be taken into consideration when delineating preventive actions in the field of public health.

[Prevalence and early determinants of common mental disorders in the 1982 birth cohort, Pelotas, Southern Brazil]

OBJECTIVE

To estimate the prevalence of common mental disorders and assess its association with risk factors in a cohort of young adults.

METHODS

Cross-sectional study nested in a 1982 birth cohort study conducted in Pelotas, Southern Brazil. In 2004-5, 4,297 subjects were interviewed during home visits. Common mental disorders were assessed using the Self-Report Questionnaire. Risk factors included socioeconomic, demographic, perinatal, and environmental variables. The analysis was stratified by gender and crude and adjusted prevalence ratios were estimated by Poisson regression.

RESULTS

The overall prevalence of common mental disorders was 28.0%; 32.8% and 23.5% in women and men, respectively. Men and women who were poor in 2004-5, regardless of their poor status in 1982, had nearly 1.5-fold increased risk for common mental disorders (p<0.001) when compared to those who have never been poor. Among women, being poor during childhood (p<0.001) and black/mixed skin color (p=0.002) increased the risk for mental disorders. Low birth weight and duration of breastfeeding were not associated to the risk of these disorders.

CONCLUSIONS

Higher prevalence of common mental disorders among low-income groups and race-ethnic minorities suggests that social inequalities present at birth have a major impact on mental health, especially common mental disorders.

[Methodology of the Pelotas birth cohort study from 1982 to 2004-5, Southern Brazil]

OBJECTIVE

To describe the methods employed in the longitudinal and follow-up studies of children born in Pelotas (Southern Brazil) in 1982.

METHODS

The cohort began with a perinatal health survey that included all 6,011 children born in maternity wards in Pelotas in 1982. The 5,914 children born alive in the city were included in the follow-up studies. By 2004-5, we had conducted eight follow-ups, which consisted of the administration of questionnaires to mothers and/or cohort members, depending on age, in addition to anthropometric and clinical examination. Cohort subjects are described in terms of demographic, socioeconomic, and health-related variables collected during early follow-up studies, which are used as exposure variables.

RESULTS

The majority of subjects in the cohort were followed for 23 years and on multiple occasions. The most successful follow-ups were those preceded by a city census. Using this method, we were able to locate 87.2% of subjects in 1984 (mean age 19 months), 84.1% in 1986 (mean age 43 months), and 77.4% in 2004-5, and 77.4% in 2004-5 (mean age 23 years).

CONCLUSIONS

Birth cohort studies can be carried out successfully in developing countries, and the methods employed in this life-cycle study have allowed us to investigate the influence of early exposures in determining disease outcomes in adult life.

[Pattern of health services utilization by adults of the Pelotas birth cohort from 1982 to 2004-5, Southern Brazil]

OBJECTIVE

To describe the pattern of health services utilization by young adults.

METHODS

Longitudinal study in Pelotas (Southern Brazil), in which the individuals were identified at birth in 1982 and followed up until 23 years of age. The outcome was defined by information collected about visits to health professionals that were attended in the year before the interview, between 2004 and 2005. The places where the visits occurred were categorized as public, private or belonging to health plan systems. Descriptive analyses were carried out for utilization and type of health service. Poisson Regression was employed in the adjusted analysis.

RESULTS

Of the interviewees, 72.0% visited health professionals in the year before the interview; 86.2% (95% CI 84.7;87.7) of the women and 59.3% (95% CI 57.3;61.3) of the men. Even when gynecological visits were excluded, the women still attended more visits than the men, 68.4% (95% CI 66.4;70.4). Health services utilization was more frequent among interviewees of better socioeconomic level. A difference of lower use in relation to non-white skin color was observed only among male youths. There were differences regarding the type of professional visited by men and women and also according to family income. Men and women used more frequently the public system, the health plan system and, in a smaller proportion, the private system.

CONCLUSIONS

The socioeconomic situation influenced the utilization and the type of health service, with men and women classified as 'poor at the moment', which indicates lower utilization of services. Such socioeconomic differences may indicate difficulties in the access to the health system.

[Determinants of early sexual initiation in the Pelotas birth cohort from 1982 to 2004-5, Southern Brazil]

OBJECTIVE

To analyze social determinants of early sexual initiation among young adults from a birth cohort.

METHODS

Individuals from the 1982 birth cohort (N=4,297) were interviewed in 2004-5, city of Pelotas, Southern Brazil. Early sexual initiation (<13 years of age) was the outcome. Descriptive and stratified analyses were performed according to sex. Variables analyzed were family income in 1982, ethnicity, young adult's level of education and change in income (between 1982 and 2004-5). Ethnographic data were used to complement result analysis.

RESULTS

Prevalence of early sexual initiation was higher among black and mixed men, and those with low level of education and low family income in 1982 and 2004-5. More traditional male sexual role requirements, such as virility and sexual initiative, showed more repercussion and adherence from an early age among men. Young family women with higher income and level of education tended to delay their sexual initiation. Imposition of traditional values was found to influence early sexual initiation among men and women with lower level of education and income.

CONCLUSIONS

Results found re-established the economic factor as a determinant of behavior or uses of sexuality for both sexes. To focus on political efforts that help the economically disadvantaged to have opportunities and egalitarian future perspectives is an important strategy for health outcomes.

[Factors associated to leisure-time sedentary lifestyle in adults of 1982 birth cohort, Pelotas, Southern Brazil]

OBJECTIVE

To assess factors associated to leisure-time physical activity and sedentary lifestyle.

METHODS

Prospective cohort study of people born in 1982 in the city of Pelotas, southern Brazil. Data were collected at birth and during in a visit in 2004-5 when 77.4% of the cohort were evaluated, making a total of 4,297 people studied. Information about leisure-time physical activity was collected using the International Physical Activity Questionnaire. Sedentary people were defined as those with weekly physical activity below 150 minutes. The following independent variables were studied: gender, skin color, birth weight, family income at birth and income change between birth and 23 years of age. Poisson's regression with robust adjustment of variance was used for the assessment of risk factors of sedentary lifestyle.

RESULTS

Men reported 334 min of weekly leisure-time physical activity compared to 112 min among women. The prevalence of sedentary lifestyle was 80.6% in women and 49.2% in men. Scores of physical activity increased as income at birth increased. Those who were currently poor or who became poor during adult life were more sedentary.

CONCLUSIONS

Leisure-time sedentary lifestyle in young adults was high especially among women. Physical activity during leisure time is determined by current socioeconomic conditions.

[Nutritional evaluation follow-up of the 1982 birth cohort, Pelotas, Southern Brazil]

OBJECTIVE

To estimate the prevalence of over/underweight and its association with demographic and socioeconomic factors.

METHODS

Longitudinal cohort study of youths born in 1982 in Pelotas, Southern Brazil. In 2004-5 we interviewed 4,198 of the 5,914 cohort subjects, obtaining weight and stature measurements that were used to calculate body mass index (BMI). Underweight was defined as BMI lower than 18,5 kg/m(2); overweight as BMI between 25 and 30kg/m(2); and obesity as BMI IMC > 30kg/m(2). The effects of socioeconomic (family income and schooling) and demographic (skin color) variables, birthweight, and breastfeeding on underweight, overweight, and obesity were analyzed separately for men and women using Poisson regression.

RESULTS

Prevalence of underweight, obesity, and overweight were 6.0%, 8.2%, and 28.9%, respectively. In adjusted analysis, only birthweight remained associated with underweight among men and women. Poor men showed higher risk of underweight, but were protected from obesity and overweight. By contrast, risk of obesity and overweight was higher among poor women.

CONCLUSIONS

The present results underscore the importance of socioeconomic determinants on nutritional status, with special emphasis on the distinct effects these factors have among men and women in different nutritional conditions.

[Early determinants of blood pressure among adults of the 1982 birth cohort, Pelotas, Southern Brazil]

OBJECTIVE

To evaluate the effects of exposure occurring during pregnancy or the first years of life on blood pressure.

METHODS

Cohort study on all children born in 1982 in maternity hospitals in the city of Pelotas, Southern Brazil. The mothers living in the urban area were interviewed and the children were followed up on different occasions. In 2004-5, all the individuals in the cohort were sought for monitoring. Their blood pressure was measured twice, at the start and end of the interview, using a digital wrist sphygmomanometer. Associations between blood pressure and the following variables were evaluated: skin color; maternal schooling level; family income at birth; change in income between birth and 23 years of age; birth weight; and duration of breastfeeding. Analysis of variance was used to compare the means and a generalized linear model was used in the adjusted analysis.

RESULTS

Blood pressure measurements were obtained from 4,291 individuals: 2,208 males and 2,083 females. The mean systolic blood pressure was 117.5 +/- 15.0 mmHg and the mean diastolic was 73.6 +/- 11.5 mmHg. Among the men, systolic blood pressure was higher among those of black or brown skin color and among those who were never considered poor. Diastolic pressure was only associated with birth weight. Among the women, systolic blood pressure was greater among those of black or brown skin color whose mothers' schooling level was greater than or equal to 12 years or whose birth weight was less than 4,000 g.

CONCLUSIONS

For both sexes, only skin color was associated with blood pressure. Breastfeeding did not have any long-term effect on blood pressure and the associations for birth weight and socioeconomic level were inconsistent.

[Prevalence of wheezing in the chest among adults from the 1982 Pelotas birth cohort, Southern Brazil]

OBJECTIVE

To estimate the prevalence of wheezing in the chest among adults, and to explore the effect of some variables on the prevalence of this condition.

METHODS

This was a prospective cohort study on individuals born in the city of Pelotas (Southern Brazil) in 1982. A total of 4,297 subjects was traced in 2004-5, representing 77.4% of the original cohort. Data were collected by means of interviews using the ISAAC (International Study of Asthma and Allergies in Childhood Steering Committee) questionnaire. Associations between the outcome 'occurrence of wheezing in the chest within the 12 months prior to the interview' and the variables of socioeconomic, demographic and birth characteristics were tested by means of multivariable analyses, using Poisson regression.

RESULTS

The prevalence of wheezing over the preceding year was 24.9%. Among the individuals reporting wheezing, 54.6% reported difficulty in sleeping, and 12.9% reported difficulty in speaking due to wheezing. The prevalence of wheezing in the chest was significantly higher among women. This association was maintained in analyses adjusted for non-white skin color, family history of asthma and low socioeconomic level. Among men, there was no significant association in the analyses adjusted for skin color and family income at birth. Family histories of asthma and poverty throughout life presented significant associations with wheezing in the chest. For both sexes, there were no associations with the variables of birth weight and breastfeeding duration.

CONCLUSIONS

The prevalence of wheezing in the chest was high, and subjects with low family income at birth were more likely to have had wheezing in the chest over the preceding year.

[Monitoring mortality in Pelotas birth cohort from 1982 to 2006, Southern Brazil]

OBJECTIVE

To assess mortality in a birth cohort followed between 1982 and 2006 and its associated factors.

METHODS

In 1982, all of the 5914 children born in hospitals in the city of Pelotas, Southern Brazil, were identified and followed up prospectively. Between 1982 and 1987, deaths were identified through regular visits to hospitals, cemeteries and death registries. As of 1987, death data were obtained through the Mortality Information System. The studied variables were: gender, color of mother, mother's schooling rate, family income, weight at birth, weight and height per age. Poisson regression was used to estimate the relative mortality risk.

RESULTS

Between 1982 and 2006 there were 288 deaths. The infant mortality coefficient was 36 deaths/1 000 live births; and in the age brackets 1-4, years, 5-14 years and 15-24 years the mortality rates were, respectively, 14.4, 4.1 and 5.4 deaths for every 1 000 live births at the beginning of the period. In all age brackets, mortality was higher for individuals from low-income families, with a relative risk of 2.89 (95% CI: 2.08; 4.03) when comparing the first and third terciles after control for gender and skin color. Low weight at birth and height-for-age and weigh-for-height deficits were found to be associated to a higher mortality rate until age 4, but not after that age.

CONCLUSIONS

The effects of social inequalities during childhood can be felt until the beginning of adult life, but birth weight and childhood nutritional status do not have a long-lasting effect on mortality rates for adolescents or young adults.

Increase in preterm births in Brazil: review of population-based studies

OBJECTIVE

The greatest cause of infant mortality in Brazil is perinatal conditions, mostly associated with preterm delivery. The objective of the study was to evaluate the evolution of preterm delivery rates in Brazil.

METHODS

A review was conducted using the Medline and Lilacs databases, including published studies in periodicals, thesis and dissertations since 1950. Exclusion criteria were: studies related to clinical trials and those with complications at gestation and preterm delivery and care. Inclusion criteria were: population-based studies on prevalence of preterm delivery in Brazil, with representative sample of the studied population, and using primary data. Out of 71 studies found, analysis was carried out on 12.

RESULTS

The prevalence of preterm delivery found ranged from 3.4% to 15.0% in the Southern and Southeastern regions between 1978 and 2004, with a rising trend from the 1990s onwards. Studies in the Northeastern region between 1984 and 1998 found prevalences of preterm delivery ranging from 3.8% to 10.2%, also with a rising trend.

CONCLUSIONS

Data from the national live birth information system do not corroborate these trends. Rather, they show differences between the preterm rates given by this system and the rates measured in the studies included in this review. Because of the important role of preterm birth in relation to infant mortality in Brazil, it is important to identify the cause of these increases and to plan interventions that can diminish their occurrence.

Intergenerational effect of weight gain in childhood on offspring birthweight

Background Some studies suggest that weight gain in childhood may increase the risk of chronic diseases in adulthood, and recent studies have noticed that the timing of weight gain may be related to its long-term consequence. However, weight gain in childhood has clear short-term benefits, and the literature on the pro and cons of weight gain in childhood is limited.

Methods In 1982, all 5914 hospital births (over 99% of all deliveries) occurring in Pelotas, Southern Brazil, were identified and studied prospectively on several occasions. In 2004–05, we attempted to trace the whole cohort and information on offspring birthweight was collected. Conditional growth modelling was used to assess the association between offspring birthweight and weight gain from birth to 20 months, and from 20 to 42 months.

Results In 2004–05, we interviewed 4297 subjects, with a follow-up rate of 77.4%. This manuscript includes data from 848 women who had already delivered a child and 525 men who were fathers at the mean age of 23 years. Maternal birthweight, weight and length for age Z-score at 20 months of age were positively associated with next-generation birthweight, whereas paternal variables were not related to the outcome. Conditional growth modelling analyses showed that women whose weight gain in the first 20 months of life was faster than predicted had heavier babies, whereas paternal weight gain was not associated. The association was strongest for mothers whose birthweight for gestational age was in the lowest tertile.

Conclusion Maternal, but not paternal birthweight and weight gain in early childhood are positively associated with next-generation birthweight.

Socioeconomic position and overweight among adolescents: data from birth cohort studies in Brazil and the UK

BACKGROUND

Developed and developing countries are facing rapid increases in overweight and obesity among children and adolescents. The patterns of overweight/obesity differ by age, sex, rural or urban residence and socioeconomic position (SEP) and vary between and within countries.

METHODS

We investigated patterns of SEP--overweight status association among adolescents from the UK (ALSPAC) and Brazil (the 1982 and 1993 Pelotas birth cohort studies). All analyses were performed separately for males and females. Logistic regression analysis was used to examine the relationships between overweight status and two SEP indicators--family income and maternal education.

RESULTS

A strong positive association was observed in 11-year-old boys from the 1993 Pelotas cohort, with higher prevalence of overweight among the least poor and among those whose mothers had more years of schooling (x2 for linear trend p < 0.001). In ALSPAC study higher prevalence of overweight was seen among boys whose mothers had lower educational achievement (x2 for linear trend p = 0.006). Among 11 year-old girls from 1993 Pelotas cohort study there was a positive association (higher prevalence of overweight in the higher socioeconomic and educational strata, x2 for linear trend p < 0.001 and p = 0.01, respectively) while an inverse association was found in the ALSPAC study (x2 for linear trend p < 0.001). Among males from the 1982 cohort study, overweight at 18 years of age showed a positive association with both SEP indicators while among females, the reverse association was found.

CONCLUSION

The results of this study demonstrate that the social patterning of overweight varies between and within populations over time. Specific approaches should be developed within populations in order to contain the obesity epidemic and reduce disparities.

The use of maternal and child health services in three population-based cohorts in Southern Brazil, 1982-2004

This study aimed to describe indicators of health care assistance during antenatal care, delivery and in the first year of life in Pelotas, Rio Grande do Sul State, Brazil. In 1982, 1993, and 2004, all hospital newborns from the urban area of Pelotas were enrolled in a cohort study. In this period, the number of pregnant women that did not attend antenatal care fell from 4.9% to 1.9%; the mean number of appointments increased from 6.7 to 8.1; and the number of women who began antenatal care in the third trimester of pregnancy decreased from 14.8% to 7%; caesarean sections increased from 27.7% to 45.2% and the proportion of deliveries assisted by physicians increased from 61.2% to 89.2%. Improvements in immunization rates during the first year of life mainly occurred between 1982 and 1993, while the number of preventive medical appointments improved among those born in 2004. This increase in coverage was greater for low-income mothers and children, which may reflect the implementation of universal coverage in Brazil; however, coverage levels in 1982 were already high for wealthy mothers and children, reducing the scope for further gains.

Maternal-child health in Pelotas, Rio Grande do Sul State, Brazil: major conclusions from comparisons of the 1982, 1993, and 2004 birth cohorts

Important changes were observed in maternal characteristics, health care indicators, and child health during the 22 years covered by the three population-based birth cohort studies conducted in the city of Pelotas, Southern Brazil. Maternal education levels improved, cigarette smoking during pregnancy was reduced, and birth intervals became longer. Also, there were more single mothers, and maternal obesity increased. Coverage of antenatal and delivery care by professionals improved, but inductions and caesarean sections increased markedly, the latter accounting for 45% of deliveries in 2004. With regard to child health, the reductions in neonatal and infant mortality rates were modest, and the significant increase in preterm births--14.7% of all births in 2004--appears to have colluded with this stagnation. Other infant health indicators, such as immunization coverage and breastfeeding duration, showed improvements over the period. Regarding infant nutrition, malnourishment at age 12 months decreased, but the prevalence of overweight was higher in 2004. The existence of three population-based birth cohorts using comparable methodology allowed for the study of important secular trends in maternal and child health.

Developmental status at age 12 months according to birth weight and family income: a comparison of two Brazilian birth cohorts

Two cohorts of children born in the city of Pelotas, Southern Brazil, in 1993 and 2004, were compared in terms of neuro-psychomotor development at the age of 12 months. Children were evaluated using the Denver II screening test. Analyses were performed using the Poisson regression technique. The prevalence of suspected developmental delay fell from 37.1% in 1993 to 21.4% in 2004 and was inversely proportional to family income and birth weight. Among children born weighing under 2,000 g, there was a fourfold reduction in the prevalence of developmental delay between 1993 and 2004. With regard to family income, the poorest group showed the greatest reduction between the two cohorts--a 30% reduction in risk. Our results confirm the influence of income and birth weight on child development. The decrease in the prevalence of developmental delay in the last decade reflects, among other factors, improvements in neonatal care, increased coverage of developmental monitoring in the first year of life, and longer breastfeeding duration. Despite this reduction, the prevalence of developmental delay is still high, reinforcing the need for early diagnosis and intervention.

Preterm births, low birth weight, and intrauterine growth restriction in three birth cohorts in Southern Brazil: 1982, 1993 and 2004

Three birth cohort studies from 1982, 1993 and 2004, in Pelotas, Southern Brazil provided the data for this study of trends in preterm births, low birth weight, and intrauterine growth restriction. We found a slight increase in the period in the low birth weight prevalence from 9% to 10%. Intrauterine growth restriction decreased from 14.8% in 1982 to 9.4% in 1993, and subsequently increased to 12% in 2004, whereas preterm births increased markedly, from 6.3% in 1982 to 14.7% in 2004. This striking increment could not be explained by changes in maternal characteristics, as mothers in 2004 were heavier, smoked less during pregnancy and attended antenatal clinics more often and earlier than those of previous cohorts. However, pregnancy interruptions due either to caesarean sections or to inductions significantly increased. Caesareans increased from 28% in 1982 to 45% in 2004, and inductions were 2.5% in 1982 but 11.1% in 2004. The increase in preterms could be partially explained by the growing number of pregnancy interruptions, but there must be other causes since this increase was also observed among babies born by non-induced vaginal deliveries.

[Education and work in the Pelotas birth cohort from 1982 to 2004-5, Southern Brazil]

OBJECTIVE

To analyze the influence of biological and socioeconomic factors throughout life on entry into the university and insertion in the work force of young adults from the 1982 birth cohort.

METHODS

Longitudinal study of 5,914 births that took place in the city of Pelotas, Southern Brazil, in 1982. Data was collected by means of questionnaires applied on young adults when accompanying the 1982 cohort in 2004-5. Information was gathered concerning educational level and insertion in the labor market. Poisson Regression was utilized to study the effect of demographic and socioeconomic variables, as well as birth weight and maternal breastfeeding, on the outcomes.

RESULTS

On the average, these young adults had 9.4 (+/- 3.1) years of schooling and 42% of them were attending school in 2004-5. One in five young adults had entered a university and approximately two thirds were working during the month prior to the interview. Entry in the university was determined by economic conditions. Furthermore, women's birth weight and breastfeeding among men influenced this outcome. Insertion in the labor market was more frequent among the poorer men, but this did not affect women's outcomes in this respect.

CONCLUSIONS

The low inclusion in the university and the need to enter the labor market among the poor families maintains a vicious circle that reproduces the dominant social hierarchy.

[Smoking prevalence in the 1982 birth cohort: from adolescence to adult life, Pelotas, Southern Brazil]

OBJECTIVE

To assess smoking prevalence in adolescents and young adults of a population-based birth cohort.

METHODS

Prospective birth cohort study of infants born in 1982, in the city of Pelotas, Southern Brazil, and interviewed in 1997, 2000-2001 and 2005. In the 1997 and 2000-2001 follow-up visits, the outcome studied was smoking, defined as the consumption of at least one cigarette in the previous week. In the 2005 follow-up visit, the dependent variable was current smoking. Adjusted analysis was performed using Poisson regression.

RESULTS

Smoking prevalences among males were 5.9%, 20.2% and 27.6% in the 1997, 2000-2001 and 2005 follow-up visits, respectively. Among females, respective values were 9.3%, 27.5% and 23.6%. Mean age of smoking onset was 15.1 years (SD=2.5). In the multivariate analysis, lower maternal level of education, low income level in 1982, poverty during the follow-up period and maternal smoking were significantly associated with higher smoking prevalences in both sexes. Being non-white was associated with higher risk of smoking among females exclusively. Breastfeeding was not associated with smoking. Among females, smoking was inversely associated with birth weight in the crude analysis, but lost its significance in the adjusted analysis.

CONCLUSIONS

Higher incidence of smoking in poorer groups suggests that behavior such as avoiding smoking during pregnancy and increasing cigarette prices can have an important population impact.

[Early determinants of random blood glucose among adults of the 1982 birth cohort, Pelotas, Southern Brazil]

OBJECTIVE

To evaluate the effects of socioeconomic variables, birth weight, duration of breastfeeding and income changes on random blood glucose levels among young adults.

METHODS

This was a study on the birth cohort from 1982, when the 5,914 hospital births that occurred in the city of Pelotas (Southern Brazil) were identified and the mothers were interviewed. The children whose families lived in the urban area of the city were followed up several times. In 2004-5, 4,927 individuals of the cohort were interviewed and blood was collected from the fingertips of 3,730 of them for random blood glucose measurements. Associations between random blood glucose levels and skin color, family income at birth, maternal schooling, income change between 1982 and 2004-5, birth weight and duration of breastfeeding were evaluated.

RESULTS

The mean blood glucose level was 97.3 +/- 15.1mg/dL, and it was greater among the men. None of the variables studied was associated with the men's blood glucose level. Among the women, maternal schooling, family income at 23 years of age and birth weight were inversely associated with blood glucose levels. However, birth weight lost its statistical significance in the multivariable analysis.

CONCLUSIONS

Birth weight and duration of breastfeeding did not present any long-term effect on random blood glucose levels. Only maternal schooling level and present income presented associations with random blood glucose levels among the women.

Influence of breastfeeding support on the tendencies of breastfeeding rates in the city of Pelotas (RS), Brazil, from 1982 to 2004

OBJECTIVE

To evaluate the influence of breastfeeding support on breastfeeding rates in the city of Pelotas (RS), Brazil.

METHODS

The prevalence rates of exclusive breastfeeding and of overall breastfeeding were compared in four cohorts of children, born in 1982, 1993, 1997-1998 and 2004. The children selected for this study fulfilled the inclusion criteria for the WHO Multicenter Growth Reference Study, in order to afford comparison with the 1997-1998 cohort, which was made up of children selected for that study. The 1997-1998 cohort received systematic breastfeeding support.

RESULTS

There was an increase in the rates of exclusive breastfeeding: from 26% at 1 month of age in 1993 to 77% at the same age in 2004, and from 16% at 3 months to 46% for the same dates, respectively. Breastfeeding rates at later ages exhibited a tendency to increase, although with less significance: from 15% in 1982 at 12 months to 34% in 2004 at the same age, and from 6% at 24 months to 14% for the same dates, respectively.

CONCLUSIONS

Breastfeeding support has contributed to a tendency for breastfeeding rates to increase.

Early life diarrhoea and later blood pressure in a developing country: the 1982 Pelotas (Brazil) birth cohort study

BACKGROUND

It has recently been hypothesised that acute dehydration in early childhood may "programme" increased blood pressure via salt retention. We examined whether there was an association between episodes of diarrhoea (a proxy for acute dehydration) and later measured blood pressure.

METHODS

In the 1982 Pelotas birth cohort study (Brazil), parents/carers reported hospital admissions for diarrhoea in the first 12 and 20 months of study members' lives. Blood pressure was subsequently measured directly in adolescence (aged 15, 18, 19 years) and early adulthood (aged 23 years).

RESULTS

We found no evidence of an association between diarrhoea in the first 12 months of life and blood pressure measured at any point in adolescence or early adulthood. These findings were unchanged after adjustment for a range of covariates. Equally null results were apparent when diarrhoea admissions in the first 20 months of life, access to home sanitation and use of piped water were the exposures of interest.

CONCLUSIONS

Early life proxies for dehydration and diarrhoea were unrelated to later blood pressure in this examination, the most comprehensive to date, of the potential association.

Associated factors and consequences of late preterm births: results from the 2004 Pelotas birth cohort

Although neonatal and infant mortality rates have fallen in recent decades in Brazil, the prevalence of preterm deliveries has increased in certain regions, especially in the number of late preterm births. This study was planned to investigate: (1) maternal antenatal characteristics associated with late preterm births and (2) the consequences of late preterm birth on infant health in the neonatal period and until age 3 months. A population-based birth cohort was enrolled in Pelotas, Southern Brazil, in 2004. Mothers were interviewed and the gestational age of newborns was estimated through last menstrual period, ultrasound and Dubowitz's method. Preterm births between 34 and 36 completed weeks of gestational age were classified as late preterm births. Only singleton live births from mothers living in the urban area of Pelotas were investigated. Three months after birth, mothers were interviewed at home regarding breast feeding, morbidity and hospital admissions. All deaths occurring in the first year of life were recorded. A total of 447 newborns (10.8%) were late preterms. Associations were observed with maternal age <20 years (prevalence ratio [PR] 1.3 [95% CI 1.1, 1.6]), absence of antenatal care (PR 2.4 [1.4, 4.2]) or less than seven prenatal care visits, arterial hypertension (PR 1.3 [1.0, 1.5]), and preterm labour (PR 1.6 [1.3, 1.9]). Compared with term births, late preterm births showed increased risk of depression at birth (Relative risk [RR] 1.7 [1.3, 2.2]), perinatal morbidity (RR 2.8 [2.3, 3.5]), and absence of breast feeding in the first hours after birth (PR 0.9 [0.8, 0.9]). RRs for neonatal and infant mortality were, respectively, 5.1 [1.7, 14.9] and 2.1 [1.0, 4.6] times higher than that observed among term newborns. In conclusion, in our setting, the prevention of all preterm births must be a priority, regardless of whether early or late.

Validation of the Edinburgh Postnatal Depression Scale (EPDS) in a sample of mothers from the 2004 Pelotas Birth Cohort Study

The aim of this study was to evaluate the Edinburgh Postnatal Depression Scale (EPDS) for screening and diagnosis of postpartum depression. Three months after delivery, EPDS was administered to 378 mothers from the 2004 Pelotas Birth Cohort Study, Rio Grande do Sul State, Brazil. Up to 15 days later, mothers were re-interviewed by mental health care professionals using a semi-structured interview based on ICD-10 (gold standard). We calculated the sensitivity and specificity of each cutoff point, and values were plotted as a receiver operator characteristic curve. The best cutoff point for screening postpartum depression was > 10, with 82.6% (75.3-89.9%) sensitivity and 65.4% (59.8-71.1%) specificity. For screening moderate and severe cases, the best cutoff point was > 11, with 83.8% (73.4-91.3%) sensitivity and 74.7% (69.4-79.5%) specificity. For diagnosis, EPDS was valid only for prevalence of postpartum depression in the 20-25% range, with 60% PPV for the > 13 cutoff point (59.5% sensitivity; 88.4% specificity). The specificities and PPVs for all cutoff points were below those reported by other authors. Small numbers and the calculation of PPV in samples with overrepresentation of cases in the majority of studies appear to account for these differences.

Continuity of behavioral and emotional problems from pre-school years to pre-adolescence in a developing country

BACKGROUND

All previous longitudinal community studies assessing the continuity of child behavioral/emotional problems were conducted in developed countries.

METHOD

Six hundred and one children randomly selected from a Brazilian birth cohort were evaluated for behavioral/emotional problems through mother interview at 4 and 12 years with the same standard procedure - Child Behavior Checklist (CBCL).

RESULTS

CBCL Total Problem score presented a medium stability (r = .42) with externalizing problems showing higher stability and more homotypic continuity than internalizing problems. Of the children presenting deviant scores at the age of 4, only 31% remained deviant at the age of 12 (p < .001). A deviant CBCL Total Problem score at 12 years old was predicted by Rule-Breaking Behavior [OR = 7.46, 95% CI 2.76-20.19] and Social Problems [OR = 3.56, 95% CI 1.36-9.30] scores at 4 years of age. Either Rule-Breaking or Aggressive Behavior - externalizing syndromes - were part of the predictors for the three broad-band CBCL scores and six out of the eight CBCL syndromes.

CONCLUSIONS

Behavioral/emotional problems in preschool children persist moderately up to pre-adolescence in a community sample. Externalizing problems at the age of 4 comprise the developmental history of most behavioral/emotional problems at pre-adolescence. Our findings concur with findings from developed countries and are quite similar for continuity, stability and predictability.