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.

Anthropometry and body composition of 18 year old men according to duration of breast feeding: birth cohort study from Brazil

OBJECTIVE

To assess the association between duration of breast feeding and measures of adiposity in adolescence.

DESIGN

Population based birth cohort study.

SETTING

Pelotas, a city of 320 000 inhabitants in a relatively developed area in southern Brazil.

PARTICIPANTS

All newborn infants in the city's hospitals were enrolled in 1982; 78.8% (2250) of all male participants were located at age 18 years when enrolling in the national army.

MAIN OUTCOME MEASURES

Weight, height, sitting height, subscapular and triceps skinfolds, and body composition (body fat, lean mass).

RESULTS

Neither the duration of total breast feeding nor that of predominant breast feeding (breast milk plus non-nutritive fluids) showed consistent associations with anthropometric or body composition indices. After adjustment for confounding factors, the only significant associations were a greater than 50% reduction in obesity among participants breast fed for three to five months compared with all other breastfeeding categories (P = 0.007) and a linear decreasing trend in obesity with increasing duration of predominant breast feeding (P = 0.03). Similar significant effects were not observed for other measures of adiposity. Borderline direct associations also occurred between total duration of breast feeding and adult height (P = 0.06).

CONCLUSIONS

The significant reduction in obesity among children breast fed for three to five months is difficult to interpret, as no a priori hypothesis existed regarding a protective effect of intermediate duration of breast feeding. The findings indicate that, in this population, breast feeding has no marked protective effect against adolescent adiposity.

Fatores associados à não realização de exame citopatológico de colo uterino no extremo Sul do Brasil

A identificação precoce do câncer de colo uterino aumenta substancialmente a sua probabilidade de cura. Este estudo mediu a prevalência e identificou alguns fatores associados à não realização de exame citopatológico de colo uterino entre mulheres em idade fértil, no Município de Rio Grande, Rio Grande do Sul, Brasil. Utilizou-se delineamento transversal, de base populacional com amostragem sistemática por conglomerados. Aplicou-se questionário individual, padronizado mediante visita domiciliar, por entrevistadores previamente treinados. Os dados foram analisados por regressão logística obedecendo a modelo hierárquico previamente determinado. Dentre as 1.302 mulheres entrevistadas, 57% nunca se submeteram ao exame citopatológico para detecção de câncer uterino. Mulheres de cor parda ou preta, de menor idade, renda familiar e escolaridade, que estavam vivendo sem companheiros e que tiveram o primeiro parto com 25 anos ou mais de idade foram as que apresentaram as maiores razões de prevalências para a não realização deste tipo de exame. A cobertura para detecção precoce de câncer de colo uterino por meio de exame citopatológico foi muito baixa em Rio Grande. Além disso, mulheres com maior probabilidade de ter esta doença foram as que apresentaram maiores razões de prevalências à sua não realização.

Early and late growth and blood pressure in adolescence

OBJECTIVE

To assess the effect of growth during infancy and childhood on blood pressure in adolescence.

DESIGN

Birth cohort study.

SETTING

Pelotas, southern Brazil.

PARTICIPANTS

749 adolescents with complete information on birth weight and gestational age, as well as on anthropometric data at all three follow up visits (mean age 20 months, 42 months, and 15 years).

MAIN OUTCOME MEASUREMENTS

Systolic and diastolic blood pressure at adolescence.

RESULTS

After controlling for possible confounding variables, birth weight was negatively associated with systolic blood pressure, one unit increase in standard deviation score of birth weight for gestational age was associated with a decrease of 1.23 mm Hg (95% confidence intervals -2.03 to -0.43) in systolic blood pressure. Weight for age z score at the age of 15 years showed a strong positive association with systolic blood pressure, one unit increase in standard deviation score of birth weight for gestational age was associated with an increase of 4.4 mm Hg (95% confidence intervals 3.50 to 5.3). Diastolic blood pressure was not associated with birth weight. For adequate for gestational age infants, the positive association between weight in adolescence and blood pressure became stronger when previous weights were added to the model.

CONCLUSION

This study showed that early--as well as--late catch up growth is associated with increased systolic blood pressure in adolescence, whereas only late catch up is related with diastolic blood pressure. These findings suggest that catch up growth, irrespective of age, is associated with increased blood pressure in adolescence.

[Infantile colic incidence and associated risk factors: a cohort study]

OBJECTIVE

To assess the incidence of infantile colic and its determinants.

METHODS

Between May and July 1999, the research team performed daily visits to the three main maternities of Pelotas. All women were interviewed after the delivery and their infants were targeted for follow-up at three months. Colic was defined according to Wessel. The following risk factors were evaluated: social class, mother's educational level, parents' age, parents' divorce, changes in the parents' relationship during pregnancy, type of delivery, reproductive history, quality of prenatal care, previous abortion, previous stillbirths, previous newborn with health problems, gender, and infant's feeding pattern. Chi-square test was used to compare proportions and conditional logistic regression was applied in the multivariate model.

RESULTS

We managed to follow 1,086 of the 1,195 infants. At the three months visit, 80.1% of the mothers reported that their infants had had colic. On the other hand, only 16.3% was considered as having colic according to Wessel criteria. Mother's educational level, father's age, type of delivery and breast-feeding duration remained in the multivariate model. Even after controlling for possible-confounding factors, the chances of having colic was 1.86 times higher among non-breastfed infants than among breastfed infants.

CONCLUSIONS

Most mothers misclassify the occurrence of colic. Breastfeeding is the main protective factor.

[Self-assessment of STD/AIDS vulnerability among women, Brazil]

OBJECTIVE

To investigate risk behaviors and self-assessment of the vulnerability to sexually transmitted diseases (STD) and acquired immunodeficiency syndrome (AIDS) among women.

METHODS

A systematic sample including 48 of 281 census tracts in the urban area of Pelotas, Brazil, was selected. There were interviewed 1,543 women, aged between 15 and 49 years, who had ever been sexually active. Risk behaviors were assessed using a confidential questionnaire that consisted of three sections: socioeconomic profile, interviewers' and self-administered questions. Data analysis was conducted using Epi-Info software, version 6.0. Statistical analysis was carried out using Kappa test and odds ratio.

RESULTS

Of all women in the sample, 64% considered impossible or almost impossible for them to acquire an STD or AIDS. The main risk behaviors were non-use of condoms in their last intercourse (72%); onset of sexual activity before age 18 years (47%); drug or alcohol use by the partner (14%) or the woman (7%) before their last intercourse; two or more partners in the last three months (7%); and anal sex in the last intercourse (3%); 44% reported two or more risk behaviors. Using a risk score of two or more points as the gold standard, sensitivity and specificity of self-assessment were 41% and 67%, respectively.

CONCLUSIONS

Self-assessment of vulnerability is not an adequate indicator of STD and AIDS vulnerability since women do not have an appropriate perception of their risks.

Factors associated with risk behaviors for sexually transmitted disease/AIDS among urban Brazilian women: a population-based study

BACKGROUND

The proportion of women among persons with sexually transmitted disease (STD)/AIDS in Brazil is increasing rapidly, and studies are needed to understand risk behaviors.

GOAL

The goal of this study was to identify factors associated with risk behaviors for acquiring STD/AIDS among women aged 15 to 49 years in Pelotas, Brazil.

STUDY DESIGN

A representative sample of women was surveyed by means of interviewer-administered and self-administered confidential questionnaires. Of the women we sought to include, 3.5% refused and 1543 participated.

RESULTS

Risk behaviors included nonuse of condoms (72%); first intercourse before the age of 18 years (47%); use of drugs or alcohol by the partner (14%) or by the woman (7%); multiple partners (7%); and anal sex (3%). The risk score was significantly associated with being younger than age 30 years, having <5 years of schooling, being divorced or separated, and being a smoker.

CONCLUSION

Preventive strategies should prioritize efforts toward young women, those with little schooling, smokers, and those who are divorced or separated.

The effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis

PURPOSE

To determine the effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis.

DESIGN

Prospective randomized open-labeled interventional clinical trial.

METHODS

A total of 124 patients with a history of recurrent toxoplasmic retinochoroiditis were randomized to treatment with one tablet of trimethoprim (160 mg)/sulfamethoxazole (800 mg) (Bactrim F; Roche Pharmaceuticals, Rio de Janeiro, Brazil) every 3 days (61 patients) or to observation without treatment (63 patients) and were followed monthly for up to 20 consecutive months for clinical signs of disease recurrence. A recurrence was defined as a new focus of necrotizing retinochoroiditis with active inflammation either adjacent to or remote from preexisting retinochoroidal scars.

RESULTS

Recurrences developed in four (6.6%) treated patients and in 15 (23.8%) controls (P =.01). Treatment was discontinued prematurely in four patients because of mild drug reactions.

CONCLUSION

Long-term intermittent treatment with trimethoprim/sulfamethoxazole can reduce the rate of recurrent toxoplasmic retinochoroiditis.

Impacto da Pastoral da Criança sobre a nutrição de menores de cinco anos no Maranhão: uma análise multinível

JUSTIFICATIVA: A Pastoral da Criança acompanha mais de 1,5 milhão de crianças mensalmente na promoção da saúde materno-infantil. Há necessidade de avaliações independentes para avaliar o seu impacto. OBJETIVO: Comparar indicadores de nutrição infantil em comunidades servidas pela Pastoral da Criança e em comunidades-controle através da análise tradicional e multinível. DELINEAMENTO: Estudo quase-experimental, comparando conglomerados de crianças acompanhadas por 60 líderes comunitárias da Pastoral e conglomerados-controle. LOCAL: Áreas urbanas e rurais (municípios São Luís e Timbiras) no Maranhão. PARTICIPANTES: 60 conglomerados em cada grupo (Pastoral e Controle) e média de 14 crianças por conglomerado, sendo efetivamente incluídas no estudo 1.629 crianças, das quais 820 eram acompanhadas pela Pastoral. RESULTADOS: A análise dos desfechos foi realizada através de métodos tradicionais, que ignoram a estrutura hierarquizada dos dados, e considerando as correlações intra-grupos através de análise multinível. Esta mostrou que a variabilidade do modelo de regressão estava distribuída em todos os 4 níveis estudados. Na análise tradicional do escore-Z de altura para idade, as crianças da Pastoral eram em média 0,184 escore-Z mais baixas do que as crianças controle (P=0,03). Após ajuste para o escore de fatores de confusão, esta diferença aumentou. No entanto, quando se ajustou para a idade das crianças o efeito diminuiu e deixou de ser significativo. A análise multinível não mostrou efeito significante da Pastoral em nenhum dos modelos de ajuste, ao contrário da análise tradicional. Tanto a análise tradicional quanto a multinível apresentaram resultados similares quanto ao desfecho de aleitamento materno exclusivo ou predominante no terceiro mês de vida, ambos evidenciando influência positiva da Pastoral da Criança, tanto na análise bruta quanto na análise ajustada (razões de odds de 4,37 e 4,63 respectivamente, ambas com p<0,001). CONCLUSÃO: A avaliação mostrou que a análise tradicional, ao ignorar as correlações intra-classes, pode apresentar resultados diversos da multinível. No presente estudo, a Pastoral da Criança esteve associada a melhoria do aleitamento materno exclusivo ou predominante, mas não em termos de altura/idade.

[Attributed risk to smoking for lung cancer, laryngeal cancer and esophageal cancer]

OBJECTIVE

Lung, laryngeal and esophageal cancers have smoking as one of their main risk factors. The objective of this study was to evaluate the population attributed risk (PAR) of smoking for these forms of cancer.

METHODS

The study was based in three case-control studies conducted in medium size cities in Brazil. Incident cases of lung cancer, laryngeal cancer and esophageal cancer seen at a hospital setting and diagnosed through biopsy were analyzed; controls were hospitalized patients with another diagnoses. Smoking was the exposure factor measured at three levels: non-smokers, former smokers and smokers, which were defined using a questionnaire applied by trained interviewers. For effect measure, odds ratio was used and the populational attributed risk for smoking was then calculated for a 95% CI.

RESULTS

A total of 122 lung cancer cases and 244 controls, 50 cases of laryngeal cancer and 48 cases of esophageal cancer, and 96 controls for both of them were studied. The prevalence of smoking exposure was 34%, which is the overall prevalence of smoking in this city's adult population. Odds ratios (OR) for the PAR analysis were the adjusted OR for confounding variables from each study. Lung cancer PAR was 63% (95% IC, 0.58-0.68) for former smokers and 71% (95%IC, 0.65-0.77) for smokers. Larynx cancer PAR was 74% (95% IC, 0.70-0.78) and 86% (95%IC, 0.81-0.85) for former smokers and smokers, respectively. Esophageal cancer PAR was 54% (95%IC, 0.46-0.62) for smokers.

CONCLUSION

Smoking is an avoidable risk factor and smoking cessation could be responsible for significant reductions in the incidence of these three forms of cancer.

[Use of health service to children under five years of age in Southern Brazil]

To identify the main determinants of health services utilization by children under five years of age, a population-based study using systematic sampling was conducted in Rio Grande, Southern Brazil. Twelve previously trained interviewers applied a standardized home questionnaire to mothers in order to obtain data on living conditions, medical consultations, and hospitalization for children under five years of age. Among 514 children covered by the study, 50% had required consultation with a physician in the previous three months and 11% had been hospitalized in the previous twelve months. Acute respiratory infection was responsible for almost two-thirds of the consultations and half of the hospitalizations. After adjusting the analysis for several confounders, the most important determinants were children's age, father's schooling, and type of home construction. Identification of these factors can contribute to adequate planning of future health interventions and to reach children in the community who need but have not received health care.

Short-term benefits of catch-up growth for small-for-gestational-age infants

BACKGROUND

Recent studies suggest that small newborns who present rapid postnatal growth may have an increased risk of chronic diseases in adulthood. On the other hand, it is widely assumed that catch-up growth is desirable for low birthweight children, but the literature on this subject is limited.

METHODS

Population-based cohort study in southern Brazil, with 3582 children examined at birth, 20 and 42 months of age. Catch-up growth from 0 to 20 months was related to subsequent risks of hospital admissions and mortality.

RESULTS

Children who were small-for-gestational-age (SGA) but presented substantial weight gain (> or =0.66 z-score) up to the age of 20 months had 65% fewer subsequent hospital admissions than other SGA children (5.6% versus 16.0%; P < 0.001). Mortality to age 5 years was 75% lower (3 versus 13 per 1000, a non-significant difference based on a small number of deaths) for rapid-growing SGA children compared to the remaining SGA children. Their admission and mortality rates were similar to those observed for children born with an appropriate birthweight for their gestational age (AGA). Similar positive effects of rapid growth were found for AGA children.

CONCLUSION

There appear to be definite benefits associated with catch-up growth. Growth promotion efforts for infants who are born small should take into account their possible short- and long-term consequences.

Ethnicity and infant health in Southern Brazil. A birth cohort study

BACKGROUND

Black children present more health problems than white children, but little information is available from less developed countries. Ethnic inequalities may vary according to country, and studies from developing countries are needed to evaluate possible differentials and their magnitude, and identify social and health interventions.

METHODS

Birth cohort study in Pelotas, Southern Brazil. Information collected during the perinatal period in hospitals, and at home at 1, 3, 6 and 12 months of age. In all, 5305 children were studied at birth, 96.8% of the sample of 1461 at 6 months, and 93.4% of this sample at 12 months of age.

RESULTS

Of the children, 28% were African Brazilian. Socioeconomic position was lower among families of black children, and mothers presented a number of unfavourable characteristics. Black children presented higher prevalences of low birthweight (LBW), preterm and small-for-gestational age (SGA), were less often immunized, had more deficits of weight-for-age and height-for-age, and higher early neonatal and infant mortality. When a number of covariates, including antenatal care, were added to a multiple regression analysis the odds ratios were markedly reduced, but there was still a clear trend towards worse results for black children. Black mothers had some aspects of antenatal care of lower quality and were submitted less frequently to caesarean sections and episiotomies.

CONCLUSIONS

Black infants experienced a much worse health status than white infants. Socioeconomic and other variables played a major role in determining inequalities between these ethnic groups. Antenatal care was especially important in explaining differentials in risk between black and white children.

Tabagismo em adolescentes de área urbana na região Sul do Brasil

OBJETIVO: Descrever a prevalência e os fatores de risco para o tabagismo em uma amostra de base populacional de adolescentes residentes em área urbana. MÉTODOS: Em 1997, realizou-se um estudo transversal com uma amostragem em múltiplos estágios dos adolescentes com idade entre 12 e 18 anos completos residentes na zona urbana da cidade de Pelotas, Rio Grande do Sul, Brasil. Foi definido como sendo fumante todo aquele adolescente que informou ter fumado pelo menos um cigarro por semana no último mês. Para as comparações entre proporções, utilizou-se o teste do qui-quadrado com correção de Yates para tabelas 2X2. A regressão logística não condicional foi utilizada na análise multivariada. RESULTADOS/ CONCLUSÕES: Foram entrevistados 632 adolescentes, sendo que com outros 38 não foi possível realizar a entrevista. Na amostra estudada, 11,1% dos adolescentes eram fumantes, 6,8% eram ex-fumantes e 82,1% nunca haviam fumado regularmente. A prevalência de tabagismo foi diretamente relacionada com a idade do adolescente. Mesmo após controle para possíveis fatores de confusão, aqueles adolescentes que não estavam estudando, que eram repetentes, cujos pais estavam separados ou que relataram terem abusado de bebidas alcoólicas no último mês apresentaram uma maior razão de odds para tabagismo.

Cocaine addicts and their families. An empirical study of the processes of identification

The processes of identification between adolescent cocaine addicts and their parents were studied in 402 subjects, in total 134 familial triads (father-mother-son), subdivided into two groups of 67 triads, one of these groups having as the child an adolescent of masculine sex dependent on cocaine and the other, equal in number, being a control group, duly matched for age and socio-economic status. The instrument employed was the Rorschach test (1922), limited to the application of the Lerner Defense Scale (LDS; Lerner & Lerner, 1980). The findings in the affected triads showed up as consistent statistically for the presence of intense processes of pathological identification, especially between father and son, a sign of the importance of the presence of disturbances of paternal function in the development of this addiction. The utilisation of very regressive defence mechanisms, above all of projective identification, was the predominant mode of procedure in triads with a dependent child. In comparisons between the fathers the odds ratio (OR) for projective identification was 8.66 to 1, which points to the association between cocaine addiction and the primitive mental functioning of the fathers. With empirical methodology these findings serve to corroborate the psychoanalytical conclusions based on studies of single case studies, testifying that the dysfunctions of identificatory phenomena in familial functioning are predominant in the mental organisation of cocaine addicts.

Maternal smoking and the risk of early weaning: a meta-analysis

OBJECTIVES

This study reviewed evidence on the effect of maternal smoking on early weaning.

METHODS

The following databases and journals were searched: Medline, Scientific Citation Index, Pediatrics, Journal of Pediatrics, New England Journal of Medicine, and Lancet. Analysis was restricted to studies in which infants who had never been breastfed were excluded or the prevalence of breastfeeding initiation was more than 90%.

RESULTS

In smoking vs nonsmoking mothers, the random effects odds ratio for weaning before 3 months was 1.93 (95% confidence interval [CI] = 1.55, 2.40). An adjusted odds ratio of 1.50 (95% CI = 1.34, 1.68) was shown in studies that had lost-to-follow-up rates below 15% and included adequate adjustment for confounding.

CONCLUSIONS

Maternal smoking increases the risk of early weaning.

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.

[Risk factors for suspicion of developmental delays at 12 months of age]

OBJECTIVE: To investigate the prevalence of positive screening test for developmental delays in a cohort of children born in Pelotas, Brazil in 1993, and their risk factors. METHODOLOGY: A sample of 20% (1,363 children) of a cohort of children born in Pelotas, Brazil, was studied at 12 months of age regarding their development. The Denver II Test was used. The children who failed in two or more items of the test were suspected of having development delay. A set of independent variables was chosen taking into account the hierarchical relations between risk factors according to the conceptual framework (socioeconomic, reproductive and environmental, birth conditions, childreńs care, nutrition and morbidity). Analyses were performed using Mantel-Haenszel X2 and multivariate technique through conditional logistic regression, to control for possible confounding. RESULTS: At 12 months of age, 34% (463) of the total of 1,363 children failed in the screening test. After adjusting for possible confounding variables, failure was associated with family lower income children (OR= 1.5), very low birth weight (OR= 4.0), gestational age less than 37 weeks (OR= 1.6), more than three siblings (OR= 1.9), and duration of breastfeeding less than three months (OR=1.6), or no breastfeeding (OR= 1.9). Children who presented weight/age at six months of age less or equal to -2 z score of the reference population presented a risk 10 times greater of having failure in the Denver II Test. CONCLUSIONS: This study reinforces the multiple etiology of development delays and the concept of cumulative risk effect. In this population those who are economically disadvantaged accumulate risk factors (social, economic and environmental) that may render to deficits in their development.

Length and ponderal index at birth: associations with mortality, hospitalizations, development and post-natal growth in Brazilian infants

BACKGROUND

Low birthweight infants suffer greater mortality and neonatal morbidity, grow less well in infancy and show poorer psycho-motor development. However, this simple categorization may obscure important differences in aetiology and prognosis between infants born stunted, thin, or both.

METHODS

In 1993, all births in Pelotas, Brazil, were enrolled into a prospective study of health and development in infancy. Of 5249 live births, 5160 had length and weight measures at birth, and were classified into tertiles of length and ponderal index. All deaths and hospitalizations were monitored, and suspected developmental delay and attained growth at 12 months were assessed on a subsample of 1364 infants. Logistic regression was used to control for gestational age and socioeconomic status.

RESULTS

There was no association between birth length and ponderal index tertiles. After adjusting for gestational age, infants in the lower tertiles of both length and ponderal index presented a 3.8-times higher risk of mortality from day 8 to day 365, and a 2.5-times higher risk of hospitalization compared to infants with greater birth lengths and/or ponderal indices. Suspected developmental delay was associated with length and, less strongly, with ponderal index, but there was no synergism between the two. Infants in the middle and upper tertiles of ponderal index at birth became thinner.

CONCLUSIONS

Birth length was strongly associated with development at 12 months, but only infants born both short and thin were at increased risk of mortality and hospitalizations. The combination of the two measures provides a useful classification of the anthropometric status of the newborn.

Breast-feeding and growth in Brazilian infants

A new international growth reference is being prepared based on children who are fed according to World Health Organization recommendations, which entail exclusive breast-feeding for the first 4-6 mo of life. However, the number of exclusively breast-fed infants in most societies is small, so that selection biases may result from using such a population. We examined the variability in linear and soft tissue growth of infants according to their feeding patterns, emphasizing differences between exclusively and predominantly (breast milk plus fluids) breast-fed infants. About 650 infants from a relatively developed urban area in southern Brazil were examined at the ages of 1, 3, 6, and 12 mo, and an additional 800 infants at 6 and 12 mo. At each visit, infants were weighed and measured and a 24-h dietary recall was completed with the infants' caretakers. In the analyses of growth, care was taken to address the biases of reverse causality, regression to the mean, and confounding. There was little association between feeding pattern and growth in the first month. From 1 to 3 mo, partially breast-fed infants tended to gain more weight, followed by those who were completely weaned. From 3 to 6 mo, fully weaned infants grew fastest in weight and length and exclusively breast-fed infants grew slowest. After 6 mo of age, the growth in length of partially breast-fed and fully weaned infants was similar, but the latter gained more weight. There were virtually no differences between exclusively and predominantly breast-fed infants in the first 6 mo of life. There results suggest that both of these groups may be pooled for the purpose of constructing growth references.

[Women's opinion on abortion legalization in a middle size county in southern Brazil]

INTRODUCTION

Induced abortion is the main cause of maternal death in Brazil. Question of its legalization has been the subject of frequent discussion.

MATERIAL AND METHOD

In order to assess the influence of the variables affecting the opinion of women of reproductive age, a population-based systematic sample in the county of Rio Grande (Southern Brazil) was examined.

RESULTS

Of a total of 1,456 interviews 30% endorsed the legalization, whatever the circumstances; this percentage was directly associated with age, schooling, family income and previous induced abortion (p < 0.01). Adjusted analysis using logistic regression showed a significant effect of schooling and previous induced abortion on favourable opinion.

CONCLUSION

Schooling and previous induced abortion were the main determinants of women's favorable opinions regarding abortion legalization.

Breast feeding, pacifier use and infant development at 12 months of age: a birth cohort study in Brazil

Many studies suggest that breast feeding confers developmental and intellectual advantages on children. In a recent study, however, no association was found between breast feeding and intelligence in adult life after adjustment for other variables, and the use of pacifier in infancy was the most important predictor of intelligence. We analysed the associations between breast-feeding duration, pacifier use and suspected developmental delay at 12 months of age in a birth cohort in Pelotas, southern Brazil. All 5304 hospital births occurring during 1993 were studied and a sample was followed up at 1, 3, 6 and 12 months of age. Breast-feeding practices and use of pacifiers were assessed at each visit, as well as suspected developmental delay, measured by the Denver II test. The prevalence of developmental delay was analysed, through logistic regression, according to breast-feeding status and pacifier use, accounting for the possible confounding effect of other variables. The prevalence of suspected developmental delay at 12 months was 34.1%, being slightly higher among children who used pacifiers at 6 months than among non-users (35.3% and 28.7% respectively). There was a marked negative association between breast-feeding duration and developmental delay, with children breast fed for 9 months or more presenting significantly less suspected developmental delay (25.5%) than those breast fed for less than 1 month (42.4%). The effects of multiple variables were tested, and only high parity, smoking during pregnancy, birthweight, gestational age, pacifier use and breast-feeding duration remained significantly associated with suspected developmental delay. The effect of pacifier use, however, disappeared after adjusting for breast-feeding duration, suggesting that breast feeding, and not pacifiers, affects child development.

Environmental tobacco smoke and breastfeeding duration

The effect of smoking on breastfeeding duration was investigated in a population-based birth cohort study of 1,098 Brazilian infants. There were few losses to follow-up (3.2%) in the first 6 months. Maternal smoking was strongly associated with breastfeeding duration, even after adjustment for confounding. Compared with nonsmokers, mothers smoking 20 or more cigarettes daily presented an odds ratio of 1.94 for breastfeeding for less than 6 months. Environmental tobacco smoke was also an independent risk factor. After adjustment for maternal smoking and other confounders, households where more than 10 cigarettes were smoked daily by persons other than the mother presented an odds ratio of 1.48 compared with those without smokers. These results remained unchanged after stratification for maternal smoking. This is the first report of a possible effect of environmental tobacco smoke on breastfeeding duration.

[Tobacco smoking among pregnant women in an urban area in southern Brazil, 1982-93]

OBJECTIVE

A comparison between on the prevalence of smoking during pregnancy in 1982 and that in 1993 in Pelotas, Southern Brazil.

METHODOLOGY

Cross-sectional study. All hospital deliveries in 1982 and 1993--corresponding to over 99% of all births in those years--were studied. A total of 6,011 and 5,304 mothers were interviewed, respectively.

RESULTS

The prevalence of smoking during pregnancy showed a small decrease from 35.7% in 1982 to 33.5% in 1993 (p < 0.05). In the two years under study, family income and number of antenatal care visits were inversely associated with the prevalence of maternal smoking. The rate of stopping smoking during pregnancy was 20.6%.

Low birthweight, preterm births and intrauterine growth retardation in relation to maternal smoking

The association between the intensity and duration of cigarette smoking during pregnancy and the frequency of low birthweight, preterm births and intrauterine growth retardation was investigated in a historical cohort. All 5166 livebirths occurring in the city of Pelotas, Brazil, during 1993 were identified and mothers interviewed soon after delivery. Children whose mothers smoked during pregnancy had a birthweight 142 g lower than those of non-smoking mothers. The odds ratio for low birthweight among children of smokers was 1.59 [95% CI 1.30-1.95]. There was no association between smoking and preterm delivery assessed by the Dubowitz score. In relation to intrauterine growth retardation, smoking was associated with an odds ratio of 2.07 [95% CI 1.69-2.53]. There was a direct dose-response association between the number of cigarettes smoked and the risk of growth retardation. Women whose partner smoked were also at higher risk of having a child with growth retardation. All the above results were adjusted for confounding factors. The effect of maternal smoking on low birthweight seems to be attributable to intrauterine growth retardation rather than preterm delivery.

[Hospitalization due to pneumonia: the influence of socioeconomic and pregnancy factors in a cohort of children in Southern Brazil]

OBJECTIVE

To investigate the influence of socioeconomic and gestational factors on admission due to pneumonia in the post-neonatal period.

METHODOLOGY

Cohort. Children born in the city Pelotas, Brazil, in 1993. Cases were children admitted to hospital for 24 hours or more, between the ages of 28 and 364 days, with a diagnosis of pneumonia.

RESULTS

Of the 5,304 children in the cohort, 152 (2.9%) were hospitalized with pneumonia. The positive predictive value of the clinical diagnosis compared to the radiological assessment was 76%. Analysis by conditional logistic regression showed that social class and maternal schooling were strongly inversely associated with pneumonia Children of adolescent mothers were twice as likely to be admitted. The relative risk for children whose mothers were of parity three or greater was 2.8 relative to primiparae. Maternal weight gain during pregnancy of less than 10 kg was associated with a 40% increase in risk.

CONCLUSION

Socioeconomic factors were important determinants of pneumonia admissions. Maternal age, parity and weight gain were also significant risk factors.

[Longitudinal study of the mother and child population in an urban region of southern Brazil, 1993: methodological aspects and preliminary results]

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.

Desenvolvimento neuropsicomotor aos 12 meses de idade em uma coorte de base populacional no Sul do Brasil: diferenciais conforme peso ao nascer e renda familiar

Os 5.304 nascimentos hospitalares ocorridos em 1993 em Pelotas, Rio Grande do Sul, foram investigados. Além da avaliação perinatal de todos os recém-nascidos, 20% (1.400 crianças) foram acompanhadas, por meio de visitas domiciliares, durante o primeiro ano. Nestas visitas, era realizado o Teste de Denver II para avaliação do desenvolvimento. Aos 12 meses, das 1.362 crianças avaliadas, 463 (34%) apresentaram teste sugestivo de atraso no desenvolvimento. Este resultado esteve associado com a renda familiar, tendo sido duas vezes mais frequente entre as crianças de famílias mais pobres do que entre as de melhor situação sócio-econômica (p<0,001). Falha no teste também esteve inversamente associada com o peso de nascimento, com as crianças de baixo peso apresentando um risco três vezes maior do que aquelas com peso ao nascer igual ou superior a 2.500g (p<0,001). Além disso, crianças que nasceram com peso inferior a 2.000g apresentaram um risco três vezes maior do que aquelas com peso entre 2.000g e 2.499g. Os resultados indicam que o peso ao nascer e a situação sócio-econômica estão fortemente associados com potenciais atrasos no desenvolvimento de crianças aos 12 meses de idade. Apontam, também, para a necessidade de triagem sistemática do desenvolvimento e programas de intervenção precoce em grupos de risco.

[Prescription of herbal teas for children under six months of age: the opinion of physicians from a middle size city in Southern Brazil]

A cross sectional study survey was carried out among physicians who work at children's clinics in Pelotas. The doctors were interviewed by medical students about the prescription of tea for children under six months, risk factors and breastfeeding. About half of the interviewed physicians prescribed tea. The main reasons for that were: intestinal colic (35%), diet supplementation (21%), and oral rehydration (18%). The relationship between tea and diarrhoea, tea and malnutrition, tea and weanning was acknowledged by 19%, 47% and 83% of them, respectively. These association remained significant (p<0.05) even after adjustments were allowed for graduation time and pos-graduation courses. The conclusion is that some common aspects of children's diet are not well managed by most of these doctors.

Desnutrição e obesidade infantis em duas coortes de base populacional no Sul do Brasil: tendências e diferenciais

Prevalências de déficits antropométricos e de obesidade foram medidas em duas coortes de nascimento de base populacional na cidade de Pelotas, Rio Grande do Sul, em 1982 e 1993, quando as crianças tinham cerca de um ano de idade. Identificados todos os nascimentos hospitalares em cada ano, cerca de 20% das crianças foram visitadas e submetidas a exame antropométrico, totalizando 1.449 crianças em 1982 e 1.359 em 1993. Houve 20% de perdas em 1982 e 7% em 1993. Em onze anos, a prevalência de déficit de peso/idade (< -2 desvios-padrão da refe-rência NCHS) caiu de 5,4% para 3,8%, a de peso/comprimento reduziu-se de 1,3% para 0,8%, enquanto que a de comprimento/idade aumentou discretamente (5,3% para 6,1%). A obesidade cresceu de 4,0% para 6,7%. Em 1993 houve um ganho ponderal médio maior, aos 12 meses, do que em 1982, já que o peso ao nascer permaneceu inalterado. Crianças de mais baixa renda apresentam prevalências de cerca de 10% de déficits de peso/idade e comprimento/idade, enquanto que nas categorias de renda superior estes déficits são de 3% ou menos. Os progressos em alguns indicadores, portanto, não lograram eliminar diferenciais sociais. Por outro lado, a obesidade apresentou uma tendência crescente com o nível de renda familiar.

Tendências e diferenciais na saúde materno-infantil: delineamento e metodologia das coortes de 1982 e 1993 de mães e crianças de 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 mães e recém-nascidos nos anos de 1982 e 1993 foram estudadas desde o nascimento. As mães foram identificadas nos hospitais-maternidade e responderam a um questionário padronizado, sendo seus filhos examinados. Mais de 99% dos recém-nascidos foram incluídos nas coortes, totalizando 5.914 nascidos vivos em 1982 e 5.249 em 1993. A mortalidade das crianças foi monitorizada, e em 1993 as hospitalizações também o foram. Em 1982, tentou-se localizar cerca de 25% das crianças aos 12 meses de idade e todas com a idade média de vinte meses. Foi possível encontrar cerca de 82% das crianças aos 12 meses e, graças a uma mudança de estratégia, 87% aos vinte meses. Em 1993, tentou-se acompanhar 20% das crianças e mais todos os recém-nascidos de baixo peso aos 12 meses de idade, sendo 95% localizados. Este artigo descreve os principais aspectos metodológicos de ambos os estudos, cujos principais resultados estão incluídos nos próximos artigos desse suplemento.

Assistência médica materno-infantil em duas coortes de base populacional no Sul do Brasil: tendências e diferenciais

Os padrões de utilização de serviços de saúde durante a gestação, o parto e o primeiro ano de vida foram analisados em duas coortes de mães e crianças, em 1982 e 1993. As coortes incluíram todos os nascimentos hospitalares ocorridos em Pelotas, Rio Grande do Sul, assim como o acompanhamento prospectivo de amostras de cerca de 20% das crianças. Reduziu-se o percentual de mães que buscaram atendimento após o quinto mês de gestação. O número médio de consultas pré-natais cresceu para 7,6. Os indicadores de assistência pré-natal foram significativamente piores para mães de baixa renda familiar e para aquelas com alto nível de risco gestacional. Em 1993, cesarianas foram realizadas em cerca de 31% dos partos, contra 28% em 1982. Os partos atendidos por médicos aumentaram para 88%. Mães pobres e de alto risco tiveram menores índices de cesarianas e de atendimento médico. As coberturas vacinais das crianças cresceram durante a década. O número médio de consultas das crianças, decresceu de 12,0 para 10,5, principalmente às custas da redução nas consultas preventivas. Embora a maior parte dos indicadores tenha mostrado progresso durante a década, os serviços de saúde seguem concentrando seus esforços nas camadas da população que deles menos necessitam.

Amamentação e padrões alimentares em crianças de duas coortes de base populacional no Sul do Brasil: tendências e diferenciais

A amamentação é fundamental para o crescimento e desenvolvimento da criança. No Brasil, a duração mediana da amamentação é muito baixa; por isso, no início da década de 80, foram implementadas campanhas nacionais de estímulo ao aleitamento materno. O presente artigo teve como objetivo avaliar as mudanças na duração da amamentação na cidade de Pelotas, Rio Grande do Sul, entre os anos de 1982 e 1993. Foram avaliados todos os nascimentos hospitalares ocorridos em ambos os anos, e amostras sistemáticas dessas crianças foram visitadas com cerca de 12 meses de idade. Observou-se um aumento na duração mediana da amamentação de 3,1 meses em 1982 para 4,0 meses em 1993. Este aumento suporta um possível impacto das campanhas nacionais ocorridas durante a década. Em ambas as coortes, houve interação entre a renda familiar e os percentuais de crianças amamentadas em diferentes idades. Nos primeiros meses, estes percentuais foram superiores nas famílias de maior renda, mas, a partir de nove meses, a amamentação foi mais freqüente no grupo de baixa renda. Crianças com baixo peso ao nascer apresentaram durações mais curtas da amamentação. Apesar dos progressos observados, a duração do aleitamento permanece bastante inferior ao recomendado internacionalmente, salientando a necessidade de campanhas futuras que priorizem crianças com baixo peso ao nascer e pertencentes às famílias de baixa renda.

Baixo peso ao nascer em duas coortes de base populacional no Sul do Brasil

As crianças com baixo peso ao nascer (menos de 2.500 g) apresentam um risco muitas vezes maior de morrer ou adoecer no primeiro ano de vida. O presente estudo teve como objetivo comparar a ocorrência de baixo peso ao nascer, nascimento pré-termo e retardo de crescimento intra-uterino, nos anos de 1982 e 1993, em Pelotas, Rio Grande do Sul. Nestes dois anos foram avaliados todos os nascimentos hospitalares, que representam mais de 99% do total dos nascimentos. O baixo peso ao nascer aumentou de 9,0% para 9,8% em 1993 (p=0,2), os nascimentos pré-termo aumentaram de 5,6% em 1982 para 7,5% em 1993 (p<0,01) e o retardo de crescimento intra-uterino passou de 15,0% em 1982 para 17,5% em 1993 (p<0,05). Nos dois períodos estudados, a renda familiar esteve inversamente associada com o risco de baixo peso e retardo de crescimento intra-uterino, mas não com nascimentos pré-termo. Em 1993, apesar da melhoria nas condições sócio-econômicas e nutricionais das mães, como também do aumento no número de consultas pré-natais, observou-se um crescimento na prevalência de baixo peso ao nascer que não foi significativa na análise bivariada. Entretanto, após ajuste para possíveis variáveis de confusão, por meio de regressão logística, houve um aumento no risco de baixo peso ao nascer da ordem de 33% (p<0,01).

[Benzodiazepines: prescription study in a primary health care unit]

PURPOSE

The objective of this survey was to study the prescription rate of benzodiazepinics in a Primary Health Care Unit, in the city of Pelotas, RS, Brazil.

METHOD

Every consultation during a 12 month period was recorded, including the prescription of drugs. In order to analyze the prescription of benzodiazepinics we considered only the 3,368 consultations of patients above 25 years.

RESULTS

Patients whose age ranged from 45-64 years experienced the highest prescription rates, benzodiazepinics being the third most prescribed drug for males and the fourth for females.

CONCLUSION

The results show that benzodiazepinics are among the most prescribed drugs.

[Smoking habits among students at the Pelotas Medical School: prevalence in 1986 and 1991]

A cross-sectional survey of smoking habits was carried out among students at the School of Medicine in Pelotas, State of Rio Grande do Sul, Brazil, in 1986 and 1991. The overall participation rate for the originally selected sample was 96% and 98% respectively. In 1986, regular smokers comprised 21.6% of the students and 14.6% in 1991; former smokers were 7.3% and 10.9%, respectively. There was no association between sex, parental smoking, and smoking habits of the students. Students in their last two years of medical training showed an increased prevalence in smoking habits (1991). Respiratory symptoms were associated with smoking habits. It was concluded that the prevalence of smoking is decreasing among students of the School of Medicine in Pelotas.

Inhibition of epidural morphine-induced pruritus by intravenous droperidol

BACKGROUND AND OBJECTIVES

Our objective was to study in more detail our previous finding that intravenous droperidol inhibits pruritus induced by epidural morphine.

METHODS

In a double blind study, 107 ASA I or II patients undergoing cesarean section received epidural anesthesia with 150 mg (30 ml) of 0.5% bupivacaine with 1:200,000 epinephrine and 2 mg of morphine hydrochloride in a single injection. They were randomly allocated to either receive (treated group, n = 54) or not receive (control group, n = 53) an intravenous injection of 2.5 mg of droperidol just after delivery. During the postoperative period, the patients were assessed for the occurrence and severity of pruritus or other possible untoward symptoms. Pruritus was classified as absent, mild, moderate, or severe.

RESULTS

The incidence of pruritus in control group was absent, 26.4%; mild, 39.6%; moderate, 28.3%; severe, 5.7%; for the treated group, the incidences were, respectively: 59.2; 27.8; 13.0; and 0.0% (p = 0.0003; Mann-Whitney test). As for other side effects of morphine, nausea and vomiting had a similar incidence in the two groups; urinary retention could not be analyzed because of bladder catheterization, and constipation, herpes labialis and clinical evidence of respiratory depression were never observed. Droperidol produced a greater incidence of somnolence (2% in control and 17% in treated group--p < 0.02; Fisher's exact test), but it was never incapacitating. The incidence of hypotension was similar in the two groups.

CONCLUSION

Intravenous droperidol reduces the incidence and severity of pruritus caused by epidural injection of morphine without inducing important side effects.

[Determinants of the smoking habit in the city of Pelotas, Brazil]

Although the harmful effects of smoking on health are well documented, this habit continues to be highly prevalent in Latin America. The objective of this study is to evaluate the frequency of this habit and its possible determinants in the adult population of the city of Pelotas, state of Rio Grande do Sul, Brazil, using a simplified methodology. With the use of a cross-sectional design, a probabilistic sample of 1,401 adults was studied; the no-response rate was 11%. Of those interviewed, 54% had never smoked, 14% were former smokers, and 33% were smokers at the time of the study; 16% smoked 20 or more cigarettes daily. Smoking was more frequent in men (44%) than in women (23%). In relation to educational level, the highest prevalence of smoking was among individuals with five to eight years of schooling (39.7%). The study showed that it is possible with a limited investment of time and resources, to evaluate the frequency of smoking in a representative sample of a medium-sized city, yielding data that will be highly useful for preventive campaigns.

Patterns of maté drinking in a Brazilian city

Maté drinking, a hot infusion of Ilex paraguayensis commonly drunk in parts of South America, has been associated with increased risks of upper digestive cancers. In a population-based survey, we have studied the patterns of maté drinking in a sample of 1400 adults living in a southern Brazilian city. Approximately one third of the population drank maté less than once a month or not at all; another third drank maté at least once a month, but less than once a day; while the remaining third drank maté daily. Daily drinking was most common among individuals aged under 60, those who migrated from rural areas, and among cigarette smokers. Drinkers ingested on average about 1800 ml/day at a mean temperature of 69.5 degrees C. Individuals who had never attended school tended to ingest larger quantities. The temperature of the drink was higher for males and for drinkers of alcoholic beverages. This information may contribute to the design of preventive interventions, since a large proportion of upper digestive cancer cases in those regions might be due to maté drinking.