Metabolic control of diabetic patients assisted by private and public health care systems during the COVID-19 pandemic: A retrospective cohort study

AIMS

We sought to analyze the impacts of social restriction measures imposed by the pandemic COVID-19 on the control of metabolic parameters in diabetic patients.

METHODS

We accessed the medical records of patients who underwent clinical follow-up in the public and private health systems between July 2019 and June 2021. The sample consisted of 288 patients (111 adults and 177 older individuals). A two-way ANOVA mixed model was used to test the effects of intra- (time: baseline and after 24 months) and inter-subject factors. Linear regression analysis was used to predict the difference in body weight considering age, sex, HbA1c, health care system and insulin use.

RESULTS

Among adults, we observed an increase in body weight and LDL-c levels, especially for insulin users (p ≤ 0.05). Adults assisted by the public health care system showed higher HbA1c levels (p = 0.001). Among older individuals using insulin, blood glucose levels decreased (p = 0.019). Body weight decreased in those assisted by the private system (p = 0.005), while glycemia decreased for patients assisted by both health care systems (p = 0.043). The linear regression model confirmed that the increase in body weight was more pronounced in adults than in older individuals.

CONCLUSION

The social restriction measures imposed by the pandemic affected the metabolic control of diabetic patients, especially adults assisted by the public health care system.

Association of the length of time using computers and mobile devices with low back, neck and mid-back pains: findings from a birth cohort

OBJECTIVES

Neck and low back pains are the leading causes of years lived with disability, and using computers or mobile devices in excess could be risk factors for back pain. Our aim was to evaluate the association of the length of time using computers and mobile devices with neck, mid-back and low back pains and the number of regions with pain.

STUDY DESIGN

Cross-sectional study nested in the 1993 Pelotas birth cohort with young adults aged 22 years.

METHODS

Outcomes analyzed were neck, mid-back and low back pains and the number of regions with pain. Exposures were the number of daily hours using computers and mobile devices. Crude and adjusted analyses were performed to estimate prevalence ratios using Poisson regression.

RESULTS

Almost half of the sample reported having back pain, the low back pain being the most prevalent. Compared with individuals using mobile devices for less than one hour, the prevalence of neck pain was 1.41 and 1.81 times higher among individuals using mobile devices from three to seven hours and for seven or more hours per day, respectively. Neck pain prevalence was 1.47 times higher among individuals using computers for more than two hours than among those not using computers. Using mobile devices for seven hours or more was associated to 1.19 times higher prevalence of low back pain.

CONCLUSION

Using mobile devices in excess was associated to neck and low back pains, while the use of computers in excess was associated only to neck pain. It is important that guidelines are developed to recommend the adequate length of time that computers and mobile devices should be used to prevent back pain.

Fetal cerebellar growth and Sylvian fissure maturation: international standards from Fetal Growth Longitudinal Study of INTERGROWTH-21st Project

OBJECTIVE

To construct international ultrasound-based standards for fetal cerebellar growth and Sylvian fissure maturation.

METHODS

Healthy, well nourished pregnant women, enrolled at < 14 weeks' gestation in the Fetal Growth Longitudinal Study (FGLS) of INTERGROWTH-21^st , an international multicenter, population-based project, underwent serial three-dimensional (3D) fetal ultrasound scans every 5 ± 1 weeks until delivery in study sites located in Brazil, India, Italy, Kenya and the UK. In the present analysis, only those fetuses that underwent developmental assessment at 2 years of age were included. We measured the transcerebellar diameter and assessed Sylvian fissure maturation using two-dimensional ultrasound images extracted from available 3D fetal head volumes. The appropriateness of pooling data from the five sites was assessed using variance component analysis and standardized site differences. For each Sylvian fissure maturation score (left or right side), mean gestational age and 95% CI were calculated. Transcerebellar diameter was modeled using fractional polynomial regression, and goodness of fit was assessed.

RESULTS

Of those children in the original FGLS cohort who had developmental assessment at 2 years of age, 1130 also had an available 3D ultrasound fetal head volume. The sociodemographic characteristics and pregnancy/perinatal outcomes of the study sample confirmed the health and low-risk status of the population studied. In addition, the fetuses had low morbidity and adequate growth and development at 2 years of age. In total, 3016 and 2359 individual volumes were available for transcerebellar-diameter and Sylvian-fissure analysis, respectively. Variance component analysis and standardized site differences showed that the five study populations were sufficiently similar on the basis of predefined criteria for the data to be pooled to produce international standards. A second-degree fractional polynomial provided the best fit for modeling transcerebellar diameter; we then estimated gestational-age-specific 3^rd , 50^th and 97^th smoothed centiles. Goodness-of-fit analysis comparing empirical centiles with smoothed centile curves showed good agreement. The Sylvian fissure increased in maturation with advancing gestation, with complete overlap of the mean gestational age and 95% CIs between the sexes for each development score. No differences in Sylvian fissure maturation between the right and left hemispheres were observed.

CONCLUSION

We present, for the first time, international standards for fetal cerebellar growth and Sylvian fissure maturation throughout pregnancy based on a healthy fetal population that exhibited adequate growth and development at 2 years of age. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Early identification of bipolar disorder among young adults - a 22-year community birth cohort

OBJECTIVE

We set forth to build a prediction model of individuals who would develop bipolar disorder (BD) using machine learning techniques in a large birth cohort.

METHODS

A total of 3748 subjects were studied at birth, 11, 15, 18, and 22 years of age in a community birth cohort. We used the elastic net algorithm with 10-fold cross-validation to predict which individuals would develop BD at endpoint (22 years) at each follow-up visit before diagnosis (from birth up to 18 years). Afterward, we used the best model to calculate the subgroups of subjects at higher and lower risk of developing BD and analyzed the clinical differences among them.

RESULTS

A total of 107 (2.8%) individuals within the cohort presented with BD type I, 26 (0.6%) with BD type II, and 87 (2.3%) with BD not otherwise specified. Frequency of female individuals was 58.82% (n = 150) in the BD sample and 53.02% (n = 1868) among the unaffected population. The model with variables assessed at the 18-year follow-up visit achieved the best performance: AUC 0.82 (CI 0.75-0.88), balanced accuracy 0.75, sensitivity 0.72, and specificity 0.77. The most important variables to detect BD at the 18-year follow-up visit were suicide risk, generalized anxiety disorder, parental physical abuse, and financial problems. Additionally, the high-risk subgroup of BD showed a high frequency of drug use and depressive symptoms.

CONCLUSIONS

We developed a risk calculator for BD incorporating both demographic and clinical variables from a 22-year birth cohort. Our findings support previous studies in high-risk samples showing the significance of suicide risk and generalized anxiety disorder prior to the onset of BD, and highlight the role of social factors and adverse life events.

International standards for fetal brain structures based on serial ultrasound measurements from Fetal Growth Longitudinal Study of INTERGROWTH-21st Project

OBJECTIVE

To create prescriptive growth standards for five fetal brain structures, measured using ultrasound, in healthy, well-nourished women at low risk of impaired fetal growth and poor perinatal outcome, taking part in the Fetal Growth Longitudinal Study (FGLS) of the INTERGROWTH-21^st Project.

METHODS

This was a complementary analysis of a large, population-based, multicenter, longitudinal study. The sample analyzed was selected randomly from the overall FGLS population, ensuring an equal distribution among the eight diverse participating sites and of three-dimensional (3D) ultrasound volumes across pregnancy (range: 15-36 weeks' gestation). We measured, in planes reconstructed from 3D ultrasound volumes of the fetal head at different timepoints in pregnancy, the size of the parieto-occipital fissure (POF), Sylvian fissure (SF), anterior horn of the lateral ventricle, atrium of the posterior horn of the lateral ventricle (PV) and cisterna magna (CM). Fractional polynomials were used to construct the standards. Growth and development of the infants were assessed at 1 and 2 years of age to confirm their adequacy for constructing international standards.

RESULTS

From the entire FGLS cohort of 4321 women, 451 (10.4%) were selected at random. After exclusions, 3D ultrasound volumes from 442 fetuses born without a congenital malformation were used to create the charts. The fetal brain structures of interest were identified in 90% of cases. All structures, except the PV, showed increasing size with gestational age, and the size of the POF, SF, PV and CM showed increasing variability. The 3^rd , 5^th , 50^th , 95^th and 97^th smoothed centiles are presented. The 5^th centiles for the POF and SF were 3.1 mm and 4.7 mm at 22 weeks' gestation and 4.6 mm and 9.9 mm at 32 weeks, respectively. The 95^th centiles for the PV and CM were 8.5 mm and 7.5 mm at 22 weeks and 8.6 mm and 9.5 mm at 32 weeks, respectively.

CONCLUSIONS

We have produced prescriptive size standards for fetal brain structures based on prospectively enrolled pregnancies at low risk of abnormal outcome. We recommend these as international standards for the assessment of measurements obtained using ultrasound from fetal brain structures. © 2020 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Adolescent parenthood associated with adverse socio-economic outcomes at age 30 years in women and men of the Pelotas, Brazil: 1982 Birth Cohort Study

OBJECTIVE

To investigate the potential long-term effects of adolescent parenthood on completed education and income.

DESIGN

Population-based birth cohort study.

SETTING

All live births in 1982, whose mothers lived in the urban area of Pelotas, southern Brazil.

SAMPLE

A total of 3701 participants: 1914 women and 1787 men at age 30 years.

METHODS

Questionnaires were completed by the mothers in the early phases of this study, and by the cohort members in adolescence and adulthood. Linear regression models and G-computation were used in the analyses.

MAIN OUTCOME MEASURES

Educational attainment and income at age 30 years.

RESULTS

In women, adolescent parenthood was associated with lower attained education compared with women without adolescent maternity: by -2.8 years [95% confidence interval (CI) -3.2 to -2.3] if their first birth was at age 16-19, and by -4.4 years (-5.5 to -3.3) at age 11-15. These effects were greater among women who had three or more children. Women with adolescent parenthood also had 49 or 33% lower income at age 30 if their first child was born when aged 16-19 or 11-15, respectively. In men, the adverse effect of adolescent parenthood on education appeared to be mediated by a higher number of children and there was no effect of adolescent paternity on income at age 30 years.

CONCLUSION

These findings suggest lasting socio-economic disadvantages of adolescent parenthood, with larger effects being apparent in women than in men.

TWEETABLE ABSTRACT

Adolescent parenthood has an adverse effect on educational attainment later in life, and on household income among women.

Quality control of ultrasound for fetal biometry: results from the INTERGROWTH-21st Project

OBJECTIVE

To assess a comprehensive package of ultrasound quality control in the Fetal Growth Longitudinal Study of the INTERGROWTH-21^st Project, a large multicenter study of fetal growth.

METHODS

Quality control (QC) measures were performed for 20 313 ultrasound scan images obtained prospectively from 4321 fetuses at 14-41 weeks' gestation in eight geographical locations. At the time of each ultrasound examination, three fetal biometric variables (head circumference (HC), abdominal circumference (AC) and femur length (FL)) were measured in triplicate on separately generated images. All measurements were taken in a blinded fashion. QC had two elements: (1) qualitative QC: visual assessment by sonographers at each study site of their images based on specific criteria, with 10% of images being re-assessed at the Oxford-based Ultrasound Quality Unit (compared using an adjusted kappa statistic); and (2) quantitative QC: assessment of measurement data by comparing the first, second and third measurements (intraobserver variability), remeasurement of caliper replacement in 10% (interobserver variability), both by Bland-Altman plots and plotting frequency histograms of the SD of triplicate measurements and assessing how many were above or below 2 SD of the expected distribution. The system allowed the sonographers' performances to be monitored regularly.

RESULTS

A high level of agreement between self- and external scoring was demonstrated for all measurements (κ = 0.99 (95% CI, 0.98-0.99) for HC, 0.98 (95% CI, 0.97-0.99) for AC and 0.96 (95% CI, 0.95-0.98) for FL). Intraobserver 95% limits of agreement (LoA) of ultrasound measures for HC, AC and FL were ± 3.3%, ± 5.6% and ± 6.2%, respectively; the corresponding values for interobserver LoA were ± 4.4%, ± 6.0% and ± 5.6%. The SD distribution of triplicate measurements for all biometric variables showed excessive variability for three of 31 sonographers, allowing prompt identification and retraining.

CONCLUSIONS

Qualitative and quantitative QC monitoring was feasible and highly reproducible in a large multicenter research study, which facilitated the production of high-quality ultrasound images. We recommend that the QC system we developed is implemented in future research studies and clinical practice. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Exploring DSM-5 ADHD criteria beyond young adulthood: phenomenology, psychometric properties and prevalence in a large three-decade birth cohort

BACKGROUND

There are still uncertainties on the psychometric validity of the DSM-5 attention deficit hyperactivity disorder (ADHD) criteria for its use in the adult population. We aim to describe the adult ADHD phenotype, to test the psychometric properties of the DSM-5 ADHD criteria, and to calculate the resulting prevalence in a population-based sample in their thirties.

METHOD

A cross-sectional evaluation using the DSM-5 ADHD criteria was carried out in 3574 individuals from the 1982 Pelotas Birth Cohort. Through receiver operator curve, latent and regression analyses, we obtained parameters on construct and discriminant validity. Still, prevalence rates were calculated for different sets of criteria.

RESULTS

The latent analysis suggested that the adult ADHD phenotype is constituted mainly by inattentive symptoms. Also, inattention symptoms were the symptoms most associated with impairment. The best cut-off for diagnosis was four symptoms, but sensitivity and specificity for this cut-off was low. ADHD prevalence rates were 2.1% for DSM-5 ADHD criteria and 5.8% for ADHD disregarding age-of-onset criterion.

CONCLUSIONS

The bi-dimensional ADHD structure proposed by the DSM demonstrated both construct and discriminant validity problems when used in the adult population, since inattention is a much more relevant feature in the adult phenotype. The use of the DSM-5 criteria results in a higher prevalence of ADHD when compared to those obtained by DSM-IV, and prevalence would increase almost threefold when considering current ADHD syndrome. These findings suggest a need for further refinement of the criteria for its use in the adult population.

The antepartum stillbirth syndrome: risk factors and pregnancy conditions identified from the INTERGROWTH-21st Project

OBJECTIVES

To identify risk factors for antepartum stillbirth, including fetal growth restriction, among women with well-dated pregnancies and access to antenatal care.

DESIGN

Population-based, prospective, observational study.

SETTING

Eight international urban populations.

POPULATION

Pregnant women and their babies enrolled in the Newborn Cross-Sectional Study of the INTERGROWTH-21^st Project.

METHODS

Cox proportional hazard models were used to compare risks among antepartum stillborn and liveborn babies.

MAIN OUTCOME MEASURES

Antepartum stillbirth was defined as any fetal death after 16 weeks' gestation before the onset of labour.

RESULTS

Of 60 121 babies, 553 were stillborn (9.2 per 1000 births), of which 445 were antepartum deaths (7.4 per 1000 births). After adjustment for site, risk factors were low socio-economic status, hazard ratio (HR): 1.6 (95% CI, 1.2-2.1); single marital status, HR 2.0 (95% CI, 1.4-2.8); age ≥40 years, HR 2.2 (95% CI, 1.4-3.7); essential hypertension, HR 4.0 (95% CI, 2.7-5.9); HIV/AIDS, HR 4.3 (95% CI, 2.0-9.1); pre-eclampsia, HR 1.6 (95% CI, 1.1-3.8); multiple pregnancy, HR 3.3 (95% CI, 2.0-5.6); and antepartum haemorrhage, HR 3.3 (95% CI, 2.5-4.5). Birth weight <3rd centile was associated with antepartum stillbirth [HR, 4.6 (95% CI, 3.4-6.2)]. The greatest risk was seen in babies not suspected to have been growth restricted antenatally, with an HR of 5.0 (95% CI, 3.6-7.0). The population-attributable risk of antepartum death associated with small-for-gestational-age neonates diagnosed at birth was 11%.

CONCLUSIONS

Antepartum stillbirth is a complex syndrome associated with several risk factors. Although small babies are at higher risk, current growth restriction detection strategies only modestly reduced the rate of stillbirth.

TWEETABLE ABSTRACT

International stillbirth study finds individual risks poor predictors of death but combinations promising.

Sugar Consumption and Changes in Dental Caries from Childhood to Adolescence

There are no prospective studies investigating the effects of sugar-related feeding practices on changes in dental caries from early childhood to young adulthood. The aim of this study was to assess whether sugar-related feeding practices affect dental caries between the ages of 6 and 18 y. This birth cohort study was initiated in 1993 in Pelotas, Brazil. There were 3 dental clinical assessments; at ages 6 y (n = 359), 12 y (n = 339), and 18 y (n = 307). Sugar-related feeding practices were assessed at ages 4, 15, and 18 y. Covariates included sex and life course variables, such as family income, breast-feeding, mother's education, regularity of dental visit, and child's toothbrushing habits. Group-based trajectory analysis was performed to characterize trajectories of time-varying independent variables that had at least 3 time points. We fitted a generalized linear mixed model assuming negative binomial distribution with log link function on 3-time repeated dental caries assessments. One in 5 participants was classified as "high" sugar consumers, and nearly 40% were "upward consumers." "Low consumers" accounted for >40% of the sample. High and upward sugar consumers had higher dental caries prevalence and mean DMFT in all cohort waves when compared with low sugar consumers. Caries occurred at a relatively constant rate over the period of study, but in all sugar consumption groups, the increment of dental caries was slightly higher between ages 6 and 12 y than between 12 and 18 y. Adjusted analysis showed that dental caries increment ratio between ages 6 and 18 y was 20% and 66% higher in upward and high sugar consumer groups as compared with low consumers. The higher the sugar consumption along the life course, the higher the dental caries increment. Even the low level of sugar consumption was related to dental caries, despite the use of fluoride.

International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown-rump length in the first trimester of pregnancy

OBJECTIVES

There are no international standards for relating fetal crown-rump length (CRL) to gestational age (GA), and most existing charts have considerable methodological limitations. The INTERGROWTH-21(st) Project aimed to produce the first international standards for early fetal size and ultrasound dating of pregnancy based on CRL measurement.

METHODS

Urban areas in eight geographically diverse countries that met strict eligibility criteria were selected for the prospective, population-based recruitment, between 9 + 0 and 13 + 6 weeks' gestation, of healthy well-nourished women with singleton pregnancies at low risk of fetal growth impairment. GA was calculated on the basis of a certain last menstrual period, regular menstrual cycle and lack of hormonal medication or breastfeeding in the preceding 2 months. CRL was measured using strict protocols and quality-control measures. All women were followed up throughout pregnancy until delivery and hospital discharge. Cases of neonatal and fetal death, severe pregnancy complications and congenital abnormalities were excluded from the study.

RESULTS

A total of 4607 women were enrolled in the Fetal Growth Longitudinal Study, one of the three main components of the INTERGROWTH-21(st) Project, of whom 4321 had a live singleton birth in the absence of severe maternal conditions or congenital abnormalities detected by ultrasound or at birth. The CRL was measured in 56 women at < 9 + 0 weeks' gestation; these were excluded, resulting in 4265 women who contributed data to the final analysis. The mean CRL and SD increased with GA almost linearly, and their relationship to GA is given by the following two equations (in which GA is in days and CRL in mm): mean CRL = -50.6562 + (0.815118 × GA) + (0.00535302 × GA(2) ); and SD of CRL = -2.21626 + (0.0984894 × GA). GA estimation is carried out according to the two equations: GA = 40.9041 + (3.21585 × CRL(0.5) ) + (0.348956 × CRL); and SD of GA = 2.39102 + (0.0193474 × CRL).

CONCLUSIONS

We have produced international prescriptive standards for early fetal linear size and ultrasound dating of pregnancy in the first trimester that can be used throughout the world.

A rapid questionnaire assessment of environmental exposures to pregnant women in the INTERGROWTH-21st Project

Impaired fetal growth and preterm birth are the leading causes of neonatal and infant mortality worldwide and there is a growing scientific literature suggesting that environmental exposures during pregnancy may play a causal role in these outcomes. Our purpose was to assess the environmental exposure of the Fetal Growth Longitudinal Study (FGLS) participants in the multinational INTERGROWTH-21(st) Project. First, we developed a tool that could be used internationally to screen pregnant women for such exposures and administered it in eight countries on a subsample (n = 987) of the FGLS participants. The FGLS is a study of fetal growth among healthy pregnant women living in relatively affluent areas, at low risk of adverse pregnancy outcomes and environmental exposures. We confirmed that most women were not exposed to major environmental hazards that could affect pregnancy outcomes according to the protocol's entry criteria. However, the instrument was able to identify some women that reported various environmental concerns in their homes such as peeling paint, high residential density (>1 person per room), presence of rodents or cockroaches (hence the use of pesticides), noise pollution and safety concerns. This screening tool was therefore useful for the purposes of the project and can be used to ascertain environmental exposures in studies in which the primary aim is not focused on environmental exposures. The instrument can be used to identify subpopulations for more in-depth assessment, (e.g. environmental and biological laboratory markers) to pinpoint areas requiring education, intervention or policy change.

Implementation of the INTERGROWTH-21st Project in Brazil

The Latin American site in the INTERGROWTH-21(st) Project was Pelotas, Brazil, with approximately 4000 births per year. The sample for the Newborn Cross-Sectional Study (NCSS) was drawn from four hospitals, covering 99% of births in the city. The Fetal Growth Longitudinal Study (FGLS) sample was recruited from one of the largest private ultrasound clinics in the city and 30 smaller, private, antenatal clinics serving middle to high socio-economic status women. Among this site's major challenges was the recruitment of women for FGLS from numerous different clinics. Several public relations activities were conducted to improve collaborative efforts between the research team and obstetricians, paediatricians and community leaders in Pelotas.

Association of socioeconomic position with maternal pregnancy and infant health outcomes in birth cohort studies from Brazil and the UK

BACKGROUND

Socioeconomic inequalities in health outcomes are dynamic and vary over time. Differences between countries can provide useful insights into the causes of health inequalities. The study aims to compare the associations between two measures of socioeconomic position (SEP)-maternal education and family income-and maternal and infant health outcomes between ALSPAC and Pelotas cohorts.

METHODS

Birth cohort studies were started in Avon, UK, in 1991 (ALSPAC) and in the city of Pelotas, Brazil, in 1982, 1993 and 2004. Maternal outcomes included smoking during pregnancy, caesarean section and delivery not attended by a doctor. Infant outcomes were preterm birth, intra-uterine growth restriction (IUGR) and breast feeding for <3 months. The relative index of inequality was used for each measure of SEP so that results were comparable between cohorts.

RESULTS

An inverse association (higher prevalence among the poorest and less educated) was observed for almost all outcomes, with the exception of caesarean sections where a positive association was found. Stronger income-related inequalities for smoking and education-related inequalities for breast feeding were found in the ALSPAC study. However, greater inequalities in caesarean section and education-related inequalities in preterm birth were observed in the Pelotas cohorts.

CONCLUSIONS

Mothers and infants have more adverse health outcomes if they are from poorer and less well-educated socioeconomic backgrounds in both Brazil and the UK. However, our findings demonstrate the dynamic nature of the association between SEP and health outcomes. Examining differential socioeconomic patterning of maternal and infant health outcomes might help understanding of mechanisms underlying such inequalities.

Espironolactone improves flow-mediated vasodilatation in subjects with the metabolic syndrome

INTRODUCTION

The role of aldosterone in the pathophysiology of the metabolic syndrome (MS)-related endothelial dysfunction has been the subject of recent research.

OBJECTIVE

To evaluate the effects of aldosterone blockade on flow-mediated vasodilation (FMD) and on renal and metabolic parameters of patients with the MS.

METHODS

19 MS subjects underwent clinical examination, laboratory work-up (serum lipid profile, glucose and insulin; creatinine clearance; microalbuminuria investigation), ambulatory blood pressure monitoring (ABPM), and FMD analysis before and after 16 weeks of aldosterone blockade with spironolactone.

RESULTS

After the treatment period, FMD increased from 7.6 ± 5.63% to 15.0 ± 6.10% (p < 0.001), associated with a non-significant decrease of blood pressure (from 142.2 ± 16.37 mmHg to 138.8 ± 16.67 mmHg, and from 84.3 ± 10.91 mmHg to 82.7 ± 9.90 mmHg, respectively). HDL-cholesterol significantly increased, microalbuminuria showed a decreasing trend and creatinine clearance did not change after treatment.

CONCLUSION

Aldosterone blockade in patients with the MS improved FMD without interfering with metabolic and renal parameters.

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.

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.

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.

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.

[Determinants of malnutrition in a low-income population: hierarchical analytical model]

To investigate the determinants of malnutrition among low-income children, the effects of socioeconomic, environmental, reproductive, morbidity, child care, birthweight and breastfeeding variables on stunting and wasting were studied. All 354 children below two years of age living in two urban slum areas of Pelotas, southern Brazil, were included. The multivariate analyses took into account the hierarchical structure of the risk factors for each type of deficit. Variables selected as significant on a given level of the model were considered as risk factors, even if their statistical significance was subsequently lost when hierarchically inferior variables were included. The final model for stunting included the variables education and presence of the father, maternal education and employment, birthweight and age. For wasting, the variables selected were the number of household appliances, birth interval, housing conditions, borough, birthweight, age, gender and previous hospitalizations.

Birth size, early childhood growth, and adolescent obesity in a Brazilian birth cohort

DESIGN

Cross-sectional visit to a subsample of a population-based birth cohort.

SAMPLE

A total of 1076 adolescents aged 14-16 y; 51% males.

MEASUREMENTS

Weight, height, subscapular and triceps skinfolds were used for assessing overweight and obesity in adolescence, using WHO-recommended criteria. Anthropometric status in early life was measured through birthweight and through weight and length/height at average ages of 20 and 43 months.

RESULTS

All analyses were adjusted for socioeconomic and maternal confounding factors. Birthweight and attained size (Z-scores of weight-for-age, height-for-age and weight-for-height) at 20 and 43 months were associated linearly and positively with overweight and obesity in adolescence. Four in each five obese adolescents were not overweight in childhood. Rapid weight gain, both between birth and 20 months, and between 20 and 43 months, was also associated with adolescent overweight and with obesity. Rapid height gain between 20 and 43 months was associated with overweight only. Most associations were stronger for boys.

CONCLUSIONS

Birth size, attained size in childhood and particularly growth velocity in early life were associated with increased prevalence of obesity and overweight in Brazilian adolescents. On the other hand, the vast majority of overweight or obese adolescents were not overweight children. Early interventions are undoubtedly important, but population-based strategies aimed at improving diets and physical activity appear to have greater long-term potential than measures targeted at overweight children.

Prevalence of abnormal eating behaviours and inappropriate methods of weight control in young women from Brazil: a population-based study

OBJECTIVE

The aim of this epidemiological investigation was to study the prevalence of abnormal eating behaviours in a community sample of young women from Porto Alegre, RS, Brazil.

METHODS

The research team visited 1524 randomly selected households in Porto Alegre and invited all of the women aged 12-29 years to participate in the study: 513 women subsequently completed a socio-economic and demographic questionnaire, the Bulimic Investigatory Test (BITE) and the Eating Attitudes Test (EAT-26).

RESULTS

Clinically significant disturbed eating behaviour was revealed in the 16.5% of women who had EAT scores above the cut-off point of 21; 2.9% also had BITE symptom scores of > or = 20. The participants were categorised into three groups on the basis of a new variable combining both instruments: those with abnormal eating behaviours (10.9%), those with unusual eating patterns (23.8%), and those with normal eating behaviours (60.2%). Abnormal eating behaviours were significantly more prevalent in the 16-19 year age range (p = 0.007) and were also more prevalent among overweight/obese women (p = 0.009). Laxative use was reported by 8.5% of the women, followed by fasting (3.1%), use of diuretics (2.8%) and vomiting (1.4%).

CONCLUSIONS

Abnormal eating behaviours are fairly common among young women in Brazil. In comparison with other population studies, this survey showed a similar use of laxatives, less self-induced vomiting and a greater use of diet pills (probably because they are less strictly controlled in Brazil). Educational programmes aimed at preventing abnormal eating behaviours and developing healthy weight control practices among children and young adolescents should become public health priorities.

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.

Comparison of two methods for assessing injuries among preschool children

BACKGROUND

Most studies of injuries use health services records or recall rather than prospective methods, and there is no information on how these different methods compare. This study was aimed at comparing a report (retrospective) with a diary (prospective) for recording childhood injuries.

METHODS

The study included 1,273 and 620 children, the retrospective and prospective subsamples, respectively, from a population based birth cohort in Pelotas, southern Brazil. The reported incidence of injuries in the preceding month were compared with those reported over month by diary (prospective study).

RESULTS

Both methods were well accepted and 92.7% of the diaries were returned. One or more injuries per child month were reported for 20.8% (retrospective) and 48.4% (prospective) of the children. The total number of reported injuries for the 620 children were 145 (retrospective) and 715 (prospective). Using the prospective method as the gold standard, the retrospective method detected only 20.2% of all injuries. Under-reporting did not vary significantly with maternal education, but was greater (51.8%) for injuries requiring medical care than for those managed at home (18.3%; p=0.003).

CONCLUSIONS

The diary was well accepted and resulted in higher incidences of reported injuries than the recall method, particularly for injuries that did not require medical care. Use of this method should be promoted to provide more complete epidemiological information to guide preventive strategies.

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.

[Health care of very low birth weight infants in Montevideo, Uruguay: a comparison between public and private sectors]

OBJECTIVE: To compare morbidity and mortality in very low birthweight infants admitted to public and private intensive care units in Montevideo, Uruguay. METHODS: Longitudinal design. All very low birth weight infants born in public hospitals of Montevideo between May 1st and October 31st, 1999, were included in the study and followed up until they were discharged from hospital, or died. The quality of care, and morbidity and mortality rates obtained in private intensive care units were compared with those observed in public intensive care units (infants who were never transferred). RESULTS: Of 141 infants, 19 were excluded from the study (13 died at the delivery room and six were transferred to intensive care units of other public hospitals). Of the remaining 122 infants, 61 were kept at the intensive care units of public hospitals, and 61 were transferred to a private unit. The infants who were transferred presented lower gestational age and increased neonatal depression. However, mortality among infants treated at intensive care units of public hospitals was twice as high (Hazard Ratio 1.8; 95%CI 1.1-3.4; P=0.04), especially in infants who weighed less than 1,000g (Hazard Ratio 2.4; 95%CI 1.1-5.5; P=0.04). CONCLUSIONS: The health status of very low birth weight infants treated at intensive care units of public and private hospitals in Montevideo, Uruguay, was assessed. Mortality was lower, and health care was better in neonatal units of private hospitals.

Infant mortality due to perinatal causes in Brazil: trends, regional patterns and possible interventions

CONTEXT

Brazilian infant and child mortality levels are not compatible with the country's economic potential. In this paper, we provide a description of levels and trends in infant mortality due to perinatal causes and malformations and assess the likely impact of changing intermediate-level determinants, many of which are amenable to direct interventions through the health or related sectors.

TYPE OF STUDY

Review paper.

METHODS

Two main sources of mortality data were used: indirect mortality estimates based on censuses and surveys, and rates based on registered deaths. The latter were corrected for under-registration. Combination of the two sources of data allowed the estimation of cause-specific mortality rates. Data on current coverage of preventive and curative interventions were mostly obtained from the 1996 Demographic and Health Survey. Other national household surveys and Ministry of Health Statistics were also used. A thorough review of the Brazilian literature on levels, trends and determinants of infant mortality led to the identification of a large number of papers and books. These provided the background for the analyses of risk factors and potential interventions.

RESULTS

The indirect infant mortality rate estimate for 1995-97 is of 37.5 deaths per thousand live births, about six times higher than in the lowest mortality countries in the world. Perinatal causes account for 57 % of all infant deaths, and congenital malformations are responsible for 11.2 % of these deaths. Mortality levels are highest in the Northeast and North, and lowest in the South and Southeast; the Center-West falls in between. Since surveys of the North region do not cover rural areas, mortality for this region may be underestimated.

CONCLUSIONS

A first priority for the further reduction in infant mortality in Brazil is to improve equality among regions, since the North and Northeast, and particularly rural areas, still show very high death rates. Further reductions in infant mortality will largely depend on decreasing deaths due to perinatal causes. Improvements in the coverage and particularly in the quality of antenatal and delivery care are urgently needed. Another intervention with a potential important impact on infant mortality is the promotion of family planning. Improving birth weight might lead to an 8 % reduction in infant mortality but the efficacy of available interventions is low.

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.

Breast-feeding has a limited long-term effect on anthropometry and body composition of Brazilian mothers

The effect of lactation on maternal nutrition is controversial. Some studies have shown that breast-feeding reduces maternal weight, whereas some have not. All studies have been restricted to the first 2 y after delivery. We investigated the effect of lactation on maternal nutrition 5 y after delivery. All mothers giving birth in the city of Pelotas, Brazil, in 1993 were interviewed and weighed soon after delivery; information was also obtained on prepregnancy weight. In 1994, information on breast-feeding duration and pattern was collected for a 20% subsample. They were seen again in 1998, and those eligible (nonsmokers, no subsequent pregnancy, last birth weight > or = 2500 g) underwent measurements for weight, height, waist, hip and arm circumferences, triceps and subscapular skinfolds. The following indices were calculated in 312 women: body mass index, waist/hip ratio, arm fat area, the percentage of body fat assessed through skinfolds, and weight and body mass index change since before conception. The percentage of body fat was also measured through bioimpedance for half of the sample. After adjustment for confounding, all outcomes generally showed a similar pattern, i.e., mothers who breast-fed for 6-11.9 mo had lower measurements than those with shorter or longer durations. However, only the association with bioimpedance was significant (P < 0.03), and that for arm fat area tended to be significant (P = 0.06). Exclusive or predominant breastfeeding at 4 mo was associated with lower waist circumference (P = 0.05) and the percentage of body fat measured through skinfolds (P = 0.04). This study suggests that the relationship between breast-feeding and long-term changes in maternal weight is complex and, in this population, not particularly strong.

[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.

[Asthmatic children's risk factors for emergency room visits, Brazil]

OBJECTIVES

To study a sample of asthmatic children to get to know how the disease is managed by caretakers and to identify predictive factors associated with attendance in emergency room for asthma.

METHODS

A cross-sectional study nested in a cohort was undertaken in the urban area of Pelotas, Southern Brazil. 981 children aged 4-5 years, who belong to the cohort of 1993, participated in this study.

RESULTS

The asthma prevalence in the children sample was 25.4%. Morbidity for asthma was quite high: 31% of the children were seen in emergency rooms in the last year, 57% attended medical clinics and 26% were hospitalized in the first 4 years of life. The crude analysis identified the following predictive factors for emergency room visits: low educational level (RO=4.1), low family income (RO=6. 5), 3 or more children sleeping in the same room (RO=2.2), severity of asthma attacks (RO=2.7), use of asthma medicines in the last year (RO=1.9) and hospitalizations due to asthma (RO=3.0). Multivariate analyses using logistic regression were used to adjust each variable for the effect of the remainder.

CONCLUSIONS

The asthma prevalence among preschool children in Pelotas is high, resulting therefore in high morbidity. The predictor factors for emergency room visits due to asthma found, after multivariate analysis, were mother's low educational level, severity of the asthma attacks and hospitalization.

[Diagnosis of overweight in adolescents: comparative study of the performance different criteria for body mass index]

OBJECTIVE

In an attempt to simplify the screening process for detecting obesity in adolescence, the performance of different cutoff values for body mass index (BMI) was assessed in a population-based cohort in Southern Brazil.

METHODS

A total of 493 adolescents aged 15-16 years who lived in the city of Pelotas, Brazil, were studied. Obesity was defined according to the WHO criteria taking into account age and sex (a BMI equal to or greater than the 85th percentile of the NHANES I reference, plus subscapular and triceps skinfold equal to or greater than the 90th percentile of the same reference). Different BMI cutoff values were used to assess their specificity and sensitivity.

RESULTS

For boys, BMI>/=25 kg/m(2) showed the best performance for detecting obesity, with a sensitivity of 90% and only 5% of false positives. The Brazilian proposed criteria that was used had 100% sensitivity but up to 23% of false positives. Higher cutoff values were also tested, but there was a slight increase in specificity, accompanied by a marked reduction in sensitivity.

CONCLUSIONS

The BMI cutoff of 25 kg/m(2) presented the best performance for screening obesity in the studied sample, and it is recommended for adolescents aged 15 and more in populations with similar characteristics. It provides a single cutoff value to be used in primary health services, eliminating the need for age and sex-specific values and skinfold measurements, and it is also consistent with the cutoff value proposed to identifying overweight adults.

[Hospitalization for bronchiolitis: a risk factor for recurrent wheezing]

This longitudinal study evaluated the role of hospitalization for acute bronchiolitis as a risk factor for recurrent wheezing. Participants were children from a 1993 cohort in a southern Brazilian city. Hierarchical multivariate analysis showed that previous hospitalization for bronchiolitis was the most important risk factor for recurrent wheezing, with an odds ratio of 4.9. This strong association is consistent with a casual relationship hypothesis.

Explaining trends in inequities: evidence from Brazilian child health studies

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

[Maternal nutrition and duration of breastfeeding in a birth cohort in Pelotas, Brazil]

OBJECTIVE

The effects of maternal nutritional status on the duration of breastfeeding are inconsistent in the literature. A population-based cohort study was set to investigate this relationship.

METHODS

Nine hundred and seventy seven mothers giving birth in 1993 (20% of that year's births) were studied. Studied maternal characteristics included nutritional status, social, economic, and demographic variables. The effects of these variables on the prevalence of breastfeeding at six months were analyzed through logistic regression. Cox regression was applied to analyze the effects on the duration of breastfeeding.

RESULTS

Multivariate logistic regression analysis showed a higher prevalence of breastfeeding among women with a pre-pregnancy weight of 49 kg or more (odds ratio = 1.31; CI(95%) 1.04 - 1.64). The association with maternal height was not significant (p=0.06). Cox regression also showed a non-significant protective effect of having a higher pre-pregnancy weight (hazard ratio = 0.91; CI(95%) 0.82 - 1.01). The duration of breastfeeding duration was not associated with maternal height. Weight gain during pregnancy was not associated with breastfeeding in either analyses. Other variables associated with the duration of breastfeeding in both analyses were maternal age, parity, smoking, and gestational age. Family income was associated with the prevalence of breastfeeding at six months, and birthweight was associated with the duration of breastfeeding.

CONCLUSIONS

Pre-pregnancy nutritional status is a stronger predictor of breastfeeding than weight gain during pregnancy.

Rates and implications of caesarean sections in Latin America: ecological study

OBJECTIVES

To estimate the incidences of caesarean sections in Latin American countries and correlate these with socioeconomic, demographic, and healthcare variables.

DESIGN

Descriptive and ecological study.

SETTING

19 Latin American countries.

MAIN OUTCOME MEASURES

National estimates of caesarean section rates in each country.

RESULTS

Seven countries had caesarean section rates below 15%. The remaining 12 countries had rates above 15% (range 16.8% to 40.0%). These 12 countries account for 81% of the deliveries in the region. A positive and significant correlation was observed between the gross national product per capita and rate of caesarean section (r(s)=0.746), and higher rates were observed in private hospitals than in public ones. Taking 15% as a medically justified accepted rate, over 850 000 unnecessary caesarean sections are performed each year in the region.

CONCLUSIONS

The reported figures represent an unnecessary increased risk for young women and their babies. From the economic perspective, this is a burden to health systems that work with limited budgets.

Increased blood pressure in adolescents who were small for gestational age at birth: a cohort study in Brazil

BACKGROUND

This paper studies the relationship between birthweight for gestational age and blood pressure in adolescents aged 14-15 years in southern Brazil.

METHODS

A sample of 1076 adolescents belonging to a cohort of over 6000 children born in 1982 in Pelotas, southern Brazil, was studied in 1997. All households in a sample of 25% of the city's census tracts were visited and all adolescents born in 1982 were interviewed, weighed, and their blood pressures were measured twice. Data from the adolescents were linked to the database through their names and dates of births.

RESULTS

High diastolic and systolic pressure (defined as >95th percentile) were significantly more frequent among adolescents who were born below the 10th percentile of birthweight for gestational age. No association was found between high blood pressure and low birthweight or preterm births. In a multiple linear regression analysis, the association between birthweight for gestational age and blood pressure was not statistically significant after adjusting for age, sex, skin colour and family income. However, when the current body mass index and height were added to the model both diastolic and systolic pressure were significantly associated with birthweight for gestational age, and adolescents who were small for gestational age at birth presented a mean elevation of 3.08 mmHg for diastolic pressure and 2.89 mmHg for systolic pressure.

CONCLUSIONS

There is an inverse association between birthweight for gestational age and blood pressure during adolescence. This association, however, is only disclosed when the negative confounding effect of the body mass index is controlled for. The same association is not found when the effects of birthweight and gestational age on blood pressure are analysed separately. It appears therefore that the elevation of blood pressure during adolescence only occurs when there was intra-uterine growth retardation.

Impact of breast feeding on admission for pneumonia during postneonatal period in Brazil: nested case-control study

OBJECTIVE

To determine whether breast feeding protects infants against pneumonia and whether the protection varies with age.

DESIGN

Nested case-control study.

SETTING

Pelotas, southern Brazil.

SUBJECTS

Cases were 152 infants aged 28-364 days who had been admitted to hospital for pneumonia. Controls were 2391 cases in a population based case-control study.

MAIN OUTCOME MEASURE

Odds ratio of admission for pneumonia according to type of milk consumed (breast milk alone, breast and formula milk, or formula milk and other fluids only), use of fluid supplements apart from formula milk, and use of solid supplements.

RESULTS

Infants who were not being breast fed were 17 times more likely than those being breast fed without formula milk to be admitted to hospital for pneumonia (95% confidence interval 7.7 to 36.0). This relative risk was 61 (19.0 to 195.5) for children under 3 months old, decreasing to 10 (2.8 to 36. 2) thereafter. Supplementation with solids was associated with a relative risk of 13.4 (7.6 to 23.5) for all infants and 175 (21.8 to 1405.1) for those under 3 months old.

CONCLUSION

Breast feeding protects young children against pneumonia, especially in the first months of life. These results may be used for targeting intervention campaigns at the most vulnerable age groups.

[Epidemiology of drug use during the first three months of life in a urban area of southern Brazil]

INTRODUCTION

The few studies on the use of medicines in children point to excessive use, and in these studies, physicians are those mainly responsible for the prescription of medicines. In order to get to know the patterns of consumption medicines better, a study was made in children in their first three months of life, according to social biological, food pattern and use of health services of variables.

METHOD

The patterns of the use of medicines during the first three months of life in 655 urban children born in Pelotas, Brazil, in 1993, were described. Information on the use of medicines was collected during a two-week period in the first and third month of life.

RESULTS

The use of medicines was reported by 65% of mothers at the 1st and 69% at the 3rd month of life. Seventeen per cent of children consumed three or more different medicines during those periods. Fixed combinations of three or more components-which was taken as an indicator of the poor of medicines quality-were consumed by 14% of the children at the 1st and 19% at the 3rd months of life. At the latter age, 20% of children had used a given medicine for one month or more. At the first month follow-up, Benzalkonium Chloride + Normal Saline Solution (nasal drops), Nystatin Mixture and Dimethicone + Homotropine were the most frequently used medicines. At the third month they were, Aspirin, Benzalkonium Chloride + Normal Saline Solution and Dimethicone + Homatropine. The main reasons for taking medicines were cramps at the first month and colds at the third. At the first month follow-up, children with three or more siblings used 64% less medicines than the older ones. Children who were not breast-fed at the end of the first month showed a 75% greater risk of use of medicines. Similar results were observed at the third month follow-up. Some of the medicines used were not recommendable for children.

CONCLUSION

Since early age children are submitted to an intense use of medicines for almost every conceivable reason, with the risk of potential side-effects and the possible lead to medicine or other drugs addiction.

The NCHS reference and the growth of breast- and bottle-fed infants

The current international growth reference, the National Center for Health Statistics (NCHS) reference, is widely used to compare the nutritional status of populations and to assess the growth of individual children throughout the world. Recently, concerns were raised regarding the adequacy of this reference for assessing the growth of breast-fed infants. We used the NCHS reference to evaluate infant growth in one of the most developed areas of Brazil. Infants who were exclusively or predominantly breast-fed for the first 4-6 mo, and partially breast-fed thereafter, grew more rapidly than the NCHS reference in weight and length during the first 3 mo, but appeared to falter thereafter. The average growth of all infants, regardless of feeding pattern, was faster than the NCHS reference until approximately 6 mo, after which their growth became slower than that of the NCHS sample. To substantiate this finding, the NCHS growth curves were then compared with growth data of breast-fed infants in developed countries from pooled published studies, formula-fed North American and European infants and predominantly bottle-fed U.S. infants monitored by the Centers for Disease Control and Prevention (CDC) Pediatric Surveillance System. In all three cases, weights showed the same pattern as the Brazilian infants-higher than NCHS in the early months but an apparent decline thereafter. The pattern for length gain was similar but less marked. Breast-fed infants showed more pronounced declines than those who were predominantly bottle-fed. These findings suggest that the infancy portion of the NCHS reference does not adequately reflect the growth of either breast-fed or artificially fed infants. This probably results from characteristics of the original sample and from inadequate curve-fitting procedures. The development of an improved international growth reference that reflects the normal infant growth pattern is indicated.

[Prenatal care in Pelotas, Rio Grande do Sul, Brazil, 1993]

All 5304 births in the hospitals of Pelotas, Rio Grande do Sul, Brazil in 1993 were studied. Neonates were examined and their mothers were interviewed regarding sociodemographic conditions, family income, reproductive health, and medical care during pregnancy. Ninety-five per cent of women received prenatal care. The mean number of physician visits during pregnancy was 7 and the majority of the women (84.7%) began visits before the fifth month of pregnancy. Women who did not receive prenatal care were from the lowest socioeconomic stratum and were mostly adolescents or over 40 years of age. Incidence of low birth weight in this group was 2.5 times that of the group with more than five visits (p>0.001). Perinatal mortality rate was 50.6/1000 in the group without prenatal care and 15.8/1000 in the group with more than five visits. With regard to utilization of health care, the study shows that twenty-five per cent of women with high gestational risk received inadequate prenatal care. The rate was less than 10% in the group of women with low gestational risk. These results suggest the need for improvement in the quality of prenatal care with special attention for mothers with high gestational risk.

[Risk factors for perinatal mortality in Pelotas, a southern city of Brazil, 1993]

INTRODUCTION

Although there was a considerable reduction in infant mortality in Pelotas, Rio Grande do Sul in the last decade, its perinatal causes were reduced only by 28%. The associated factors of these causes were analysed.

MATERIAL AND METHOD

All hospital births and perinatal deaths were assessed by daily visits to all the maternity hospitals in the city, throughout 1993 and including the first week of 1994.

RESULTS

The perinatal mortality rate was 22.1 per thousand births. The multivariate analysis showed the following risk factors: low socioeconomic level, male sex and maternal age above 35 years. Among multigravidae women, the fetal mortality rate was significantly increased for mothers with a previously low birthweight and a previous stillbirth. For early neonatal mortality the risk was significantly increased by a smaller number of antenatal visits than 5 and low birthweight.

CONCLUSIONS

Main risk factors for perinatal mortality: low socioeconomic level, maternal age above 35 years and male sex. For early neonatal mortality the risk was significantly increased by a smaller number of antenatal visits than 5 and low birthweight.

[Incidence and duration of breast-feeding by type of delivery: a longitudinal study in southeastern of Brazil]

OBJECTIVE

To compare the incidence of breastfeeding according to type of delivery.

METHODOLOGY

Population-based cohort study of 655 children born in 1993 and followed up during the first three months of life through home visits.

RESULTS

Breastfeeding duration was similar among babies born either by vaginal delivery or by emergency cesarean section. Babies born by elective cesarean section, however, presented a three times higher risk of stopping breastfeeding in the first month of life, after adjusting for possible confounding factors (odds ratio = 3.09; 95% CI 1.3-7.2). The increased risk did not persist into the third month of life.

CONCLUSIONS

It is recommended that health services pay special attention, in the promotion of breastfeeding, to babies born by elective cesarean section, as a way to avoid early weaning.