Previous studies have found greater adiposity and cardiovascular risk in first born children. The causality of this association is not clear. Examining the association in diverse populations may lead to improved insight.
We examine the association between birth order and body mass index (BMI), systolic and diastolic blood pressure (SBP/DBP) in the 2004 Pelotas cohort from southern Brazil and the Avon Longitudinal Study of Parents and Children (ALSPAC) from Bristol, south west England, restricting analysis to families with two children in order to remove confounding by family size.
No consistent differences in BMI, SBP or DBP were observed comparing first and second born children. Within the Pelotas 2004 cohort, first born females were thinner, with lower SBP and DBP; e.g. mean difference in SBP comparing first with second born was -0.979 (95% confidence interval -2.901 to 0.943). In ALSPAC, first born females had higher BMI, SBP and DBP. In both cohorts, associations tended to be in the opposite direction in males, although no statistical evidence for gender interactions was found.
The findings do not support an association between birth order and BMI or blood pressure. Differences to previous studies may be explained by differences in populations and/or confounding by family size in previous studies.
ALSPAC; birth order; blood pressure; body mass index; cardiovascular; obesity; Pelotas; siblings
To describe the patterns of deliveries in a birth cohort and to compare vaginal and cesarean section deliveries.
All children born to mothers from the urban area of Pelotas, Brazil, in 2004, were recruited for a birth cohort study. Mothers were contacted and interviewed during their hospital stay when extensive information on the gestation, the birth and the newborn, along with maternal health history and family characteristics was collected. Maternal characteristics and childbirth care financing – either private or public healthcare (SUS) patients - were the main factors investigated along with a description of C-sections distribution according to day of the week and delivery time. Standard descriptive techniques, χ2 tests for comparing proportions and Poisson regression to explore the independent effect of C-section predictors were the methods used.
The overall C-section rate was 45%, 36% among SUS and 81% among private patients, where 35% of C-sections were reported elective. C-sections were more frequent on Tuesdays and Wednesdays, reducing by about a third on Sundays, while normal deliveries had a uniform distribution along the week. Delivery time for C-sections was markedly different among public and private patients. Maternal schooling was positively associated with C-section among SUS patients, but not among private patients.
C-sections were almost universal among the wealthier mothers, and strongly related to maternal education among SUS patients. The patterns we describe are compatible with the idea that C-sections are largely done to suit the doctor’s schedule. Drastic action is called for to change the current situation.
Parturition; Cesarean Section, trends; Perinatal Care; Obstetrics; Socioeconomic Factors; Cohort Studies.
Maternal physical activity during pregnancy could alter offspring's IQ and neurodevelopment in childhood.
Children belonging to a birth cohort were followed at 3, 12, 24 and 48 months of age. Physical activity during pregnancy was assessed retrospectively at birth. Neurodevelopment was evaluated by Battelle's Development Inventory (12, 24 and 48 months) and IQ by the Weschler's Intelligence Scale (48 months). Neurodevelopment was based on Battelles' (90th percentile) and also analyzed as a continuous outcome. IQ was analyzed as a continuous outcome. Potential confounders were: family income, mother's age, schooling, skin color, number of previous births and smoking; and newborns': preterm birth, sex and low birth weight.
From birth to 48 months, sample size decreased from 4231 to 3792. Crude analysis showed that IQ at 48 months was slightly higher (5 points) among children from active women. The Battelle's score at 12 and 24 months was higher among offspring from active mothers. After controlling for confounders, physical activity during pregnancy was positively associated to the Battelle's Inventory at 12 months IQ, however, at 48 months no association was observed.
Physical activity during pregnancy does not seem to impair children's neurodevelopment and children from active mothers presented better performance at 12 months.
Maternal mood symptoms have been associated with psychiatric disorders in children. This study aimed to assess critical periods when maternal symptoms would be more deleterious.
Cohort of 4231 births followed-up in the city of Pelotas, Brazil. Mood symptoms during pregnancy were self-reported by mothers at perinatal interview; and at 3-months postpartum, mothers answered the Self-Reporting Questionnaire. Psychiatric disorders in 6-year-old children were evaluated through the Development and Well-Being Assessment instrument. Odds ratios with 95% confidence intervals (95% CI) were calculated by logistic regression.
Prevalence of mood symptoms in pregnancy was 24.6% (23.2–26.0%) and at three months postpartum 22.5% (21.1–23.9%). Prevalence of mental disorders in children was 13.3% (12.2–14.4%). After adjustment for confounders children of mothers with mood symptoms during pregnancy were 82% more likely of presenting psychiatric disorders than children of mothers that did not (1.82; 1.48–2.25); and the chance of having mental disorders among children whose mothers had positive SRQ-20 at three months postpartum was 87% greater than the observed among children whose mothers had it negative (1.87; 1.50–2.33).
Because maternal anxiety/depression may interfere with interpretation of the child behavior, child׳s mental health being obtained by interviewing the mother is a limitation of this study. Lack of information on other risk factors may have lead to residual confounding on the effect of maternal mood symptoms at three months postpartum.
Children of mothers presenting mood symptoms during pregnancy and in the first months postpartum are more likely to present psychiatric disorders at 6 years of age.
DAWBA, Development and Well- Being Assessment; EPDS, Edinburgh Post-natal Depression Scale; LBW, low birth weight; LMP, last menstrual period; OR, odds ratio; MW, minimum wages; SRQ-20, self-reporting questionnaire; 95% CI, 95% confidence interval; Mood disorders; Self-reporting questionnaire; Development and Well-Being Assessment; Cohort study; Preschool children
Most studies published on the prevalence of psychiatric disorders in children were conducted in high-income countries despite the fact that nearly 90 % of the world’s population aged under 18 live in low- and middle-income countries. The study aimed to assess the prevalence of psychiatric disorders among children of 6 years of age, to examine the distribution of psychiatric disorders by gender and socioeconomic status and to evaluate the occurrence of psychiatric comorbidities.
The 2004 Pelotas Birth Cohort originally comprised 4,231 live births from Pelotas, southern Brazil. A total of 3,585 (84.7 % of 4,231 births) children aged 6 years were assessed using the Development and Well-Being Assessment (DAWBA).
Nearly 13 % of the children presented a psychiatric diagnosis according to DSM-IV, being more prevalent among males than females (14.7 and 11.7 %, respectively, p = 0.009). Anxiety disorders were the most prevalent of all disorders (8.8 %) and specific phobias (5.4 %) and separation anxiety disorder (3.2 %) were the most common subtypes. Attention deficit hyperactivity disorder (2.6 %), oppositional defiant disorder/conduct disorder (2.6 %), and depression (1.3 %) were also diagnosed. More than one psychiatric disorder was presented by 17 % of children. Socioeconomically disadvantaged children had a higher prevalence of psychiatric disorders.
Our findings underline the early onset of psychiatric disorders among children and the frequent occurrence of psychiatric comorbidity. Early prevention is needed in the field of mental health in Brazil and should start during infancy.
Prevalence; Cohort studies; Mental disorders; Mental health; Child
To describe the meals consumed by adults living in a midsize city in the
South of Brazil, according to the place and preparation.
A population-based cross-sectional study was conducted in Pelotas, Southern
Brazil, in 2012. The two-stage sampling design used the 2010 census tracts
as primary sampling units. Data were collected on the place of meals (at
home or out) and on the kind of preparations consumed at home (homemade,
snacks, take away food) covering the two days prior to the interview, using
a standardized questionnaire.
The study included 2,927 adults, of which 59.0% were female, 60.0% were below
50 years of age and 58.0% were in work. Data were collected on 11,581 meals
consumed on the two days preceding the interview, 25.0% were consumed
outside of the home at lunchtime, and 10.0% at dinnertime. Considering home
meals, most participants reported eating food prepared at home at both lunch
and dinner. The majority of out-of-home meals (64.0% for lunch and 61.0% for
dinner) were consumed in the work place, mostly based on food prepared at
home. Individuals eating out of home were mostly male, young and highly
educated. The occupational categories that ate at restaurants more often
were trade workers, businessmen, teachers and graduate professionals.
Despite the changes in eating patterns described in Brazil in recent years,
residents of medium-sized towns still mostly eat at home, consuming homemade
Food Habits; Food Consumption; Feeding Behaviour; Population Surveys; Cross-Sectional Studies
To analyze the effectiveness of motivational interviewing (MI) at improving
oral health behaviors (oral hygiene habits, sugar consumption, dental
services utilization or use of fluoride) and dental clinical outcomes
(dental plaque, dental caries and periodontal status).
A systematic search of PubMed, LILACS, SciELO, PsyINFO, Cochrane and Google
Scholar bibliographic databases was conducted looking for intervention
studies that investigated MI as the main approach to improving the oral
health outcomes investigated.
Of the 78 articles found, ten met the inclusion criteria, all based on
randomized controlled trials. Most studies (n = 8) assessed multiple
outcomes. Five interventions assessed the impact of MI on oral health
behaviors and nine on clinical outcomes (three on dental caries, six on
dental plaque, four on gingivitis and three on periodontal pockets). Better
quality of evidence was provided by studies that investigated dental caries,
which also had the largest population samples. The evidence of the effect of
MI on improving oral health outcomes is conflicting. Four studies reported
positive effects of MI on oral health outcomes whereas another four showed
null effect. In two interventions, the actual difference between groups was
not reported or able to be recalculated.
We found inconclusive effectiveness for most oral health outcomes. We need
more and better designed and reported interventions to fully assess the
impact of MI on oral health and understand the appropriate dosage for the
Motivational Interviewing, utilization; Health Behavior; Patient Acceptance of Health Care; Health Promotion, methods; Oral Health; Review
In a PLOS Medicine Review, Aluísio Barros and Cesar Victora provide a practical guide to measuring and interpreting inequalities in the coverage of maternal, newborn, and child interventions in low- and middle-income countries using data collected by large household surveys.
To monitor progress towards the Millennium Development Goals, it is essential to monitor the coverage of health interventions in subgroups of the population, because national averages can hide important inequalities. In this review, we provide a practical guide to measuring and interpreting inequalities based on surveys carried out in low- and middle-income countries, with a focus on the health of mothers and children. Relevant stratification variables include urban/rural residence, geographic region, and educational level, but breakdowns by wealth status are increasingly popular. For the latter, a classification based on an asset index is the most appropriate for national surveys. The measurement of intervention coverage can be made by single indicators, but the use of combined measures has important advantages, and we advocate two summary measures (the composite coverage index and the co-coverage indicator) for the study of time trends and for cross-country comparisons. We highlight the need for inequality measures that take the whole socioeconomic distribution into account, such as the relative concentration index and the slope index of inequality, although simpler measures such as the ratio and difference between the richest and poorest groups may also be presented for non-technical audiences. Finally, we present a framework for the analysis of time trends in inequalities, arguing that it is essential to study both absolute and relative indicators, and we provide guidance to the joint interpretation of these results.
To identify prognostic factors associated with recurrence of low birthweight (LBW) in successive gestations, a study was carried out with a subsample of mothers enrolled in the 2004 Pelotas Birth Cohort.
Data were collected by hospital-based interviews. Newborns were weighed and measured. Gestational age was defined according to the date of last menstrual period, ultra-sound scan before the 20th week of pregnancy or the Dubowitz method. Mothers who reported at least one LBW newborn in the two previous gestations were included. Prevalence ratios (PR) and 95% confidence intervals were estimated from Poisson Regression. All estimates were adjusted for parity.
A total of 4558 births were identified in 2004, and 565 met inclusion criteria, out of which 86 (15.2%) repeated LBW in 2004. Among mothers with two LBW babies before 2004, 47.9% presented LBW recurrence. Belonging to the highest socio-economic stratum (PR 0.89; 0.01-0.46) and gaining ≥ 10 kg during pregnancy (PR 0.09; 0.01-0.77) were protective against LBW recurrence. Higher risk of LBW recurrence was observed among mothers with higher parity (≥3 previous deliveries; PR=1.93; 95% CI 1.23-3.02); who had given birth to a previous preterm baby (PR=4.01; 2.27-7.10); who delivered a female newborn in current gestation (PR=2.61; 1.45-4.69); and that had not received adequate antenatal care (PR=2.57; 1-37-4.81).
Improved quality of antenatal care and adequate maternal weight gain during pregnancy may be feasible strategies to prevent LBW repetition in successive pregnancies.
Prognostic factors; Low birthweight recurrence; Low birthweight; Preterm; Antenatal care
Background. To estimate the exposure to medicines with unknown fetal risk during pregnancy and to analyze the maternal characteristics associated with it. Methods. A questionnaire was administered to 4,189 mothers of children belonging to the 2004 Pelotas (Brazil) birth cohort study about use of any medicine during gestation. We evaluated the associations between use of medicines with unknown fetal risk and the independent variables through logistic regression models. Unknown fetal risk was defined as medicines in which studies in animals have revealed adverse effects on the fetus, and no controlled studies in women, or studies in women and animals, are available. Results. Out of the 4,189 women, 52.5% used at least one medicine from unknown fetal risk. Use of these medicines was associated with white skin color, high schooling, high income, six or more antenatal care consultations, hospital admission during pregnancy, and morbidity during gestation. Conclusion. The use of unknown fetal risk medicines is high, suggesting that their use must be addressed with caution with the aim of restricting their use to cases in which the benefits are greater than the potential risks.
Socioeconomic inequalities in child nutrition may change rapidly over time, particularly in populations undergoing the nutrition transition. Yet, the few available studies are repeated cross-sectional surveys. By studying three prospective birth cohorts in the same city over a period of more than two decades, we describe secular trends in overweight and stunting at different ages, according to socioeconomic position.
Population-based birth cohort studies were launched in the city of Pelotas (Brazil) in 1982, 1993 and 2004, with follow-up visits at twelve, 24 and 48 months. Children were weighed and measured at every visit. Z-scores of length/height-for-age and body mass index-for-age were calculated using the WHO Child Growth Standards. The slope and relative indices of inequality, based on family income quintiles, were estimated for each follow-up visit.
Between the 1982 and 2004 cohorts, stunting among four-year-olds declined (from 10.9% to 3.6%), while overweight increased (from 7.6% to 12.3%). In every visit, stunting prevalence was inversely related to income. Both absolute and relative inequalities declined over time; among four-year-olds stunting dropped from 26.0% in the 1982 cohort to 6.7% in the 2004 cohort in the poorest group, while in the richest group stunting prevalence dropped from 2.7% in 1982 to 1.1% in the 2004 cohort study. The secular trend towards increased overweight was evident for four-year-olds, in almost all socioeconomic groups, but not among one and two-year-olds. Among four-year old children, overweight prevalence increased in all income quintiles, by 130% in the middle-income group, 64% in the poorest and 41% in the richest group.
The decline in stunting is remarkable, but the increase in overweight among four-year olds – particularly among the poorest and the middle-income groups– requires concerted efforts to prevent the long term consequences of child overweight.
Socioeconomic factors; Health status disparities; Cohort studies; Child nutrition; Overweight; Stunting
To explore the effects of maternal smoking during pregnancy on offspring growth using three approaches: (1) multiple adjustments for socioeconomic and parental factors, (2) maternal–paternal comparisons as a test of putative intrauterine effects and (3) comparisons between two birth cohort studies.
Population-based birth cohort studies were carried out in Pelotas, Brazil, in 1993 and 2004. Cohort members were followed up at 3, 12, 24 and 48 months. Multiple linear regression analysis was used to examine the relationships between maternal and paternal prenatal smoking and offspring anthropometric indices. In the 2004 cohort, the association of smoking with trunk length, leg length and leg-to-sitting-height ratio at 48 months was also explored.
Maternal smoking during pregnancy was associated with reduced z scores of length/height-for-age at each follow-up in both cohorts and reduced leg length at 48 months in the 2004 cohort. Children older than 3 months born to smoking women showed a higher body mass index-for-age z score than children of non-smoking women.
The results of this study strongly support the hypothesis that maternal smoking during pregnancy impairs linear growth and promotes overweight in childhood.
To investigate the association between sustained maternal depression at 12, 24, and 48 months post-partum and child anthropometry at age of 4 years.
A total of 99.2% of the 4287 children born in 2004 in Pelotas, Brazil, were enrolled in a cohort study. At 3, 12, 24, and 48 months, mothers were interviewed and provided information on several characteristics. Maternal depression was investigated through the Edinburgh Postnatal Depression Scale (EPDS). Weight-for-age, height-for-age, and weight-for-height z-scores at 48 months, according to World Health Organization growth curves, were the outcomes. Multivariate analyses were conducted through logistic regression.
At the 48-month follow-up, of the 3792 children, prevalence of underweight was 1.7%; stunting, 3.6%; wasting, 0.6%; and overweight, 12.2%. Depression (EPDS ≥13) was observed in 17.9% of the 3748 mothers. Of the mothers, 4.7% were persistently depressed at the 12-, 24-, and 48-month visits. In crude analyses, maternal depression was positively associated with underweight and stunting. After adjustment, maternal depression was not associated with any of the anthropometric indices.
Long-lasting maternal depression at 12, 24, and 48 months post-partum is not a risk factor for impaired child growth or overweight at age of 4 years.
BMI, Body mass index; EPDS, Edinburgh Postnatal Depression Scale; GA, Gestational age; H/A, Height-for-age; LBW, Low birth weight; LMP, Last menstrual period; W/A, Weight-for-age; W/H, Weight-for-height; WHO, World Health Organization
To investigate the association between bedsharing at age 3 months and breastfeeding (BF) at age 12 months.
Almost all children born in Pelotas, Brazil in 2004 (99.2%) were enrolled in a cohort study. At birth, age 3 months, and age 12 months, mothers were interviewed to gather information on sociodemographic, reproductive, BF, and bedsharing characteristics. Bedsharing was defined as habitual sharing of a bed between mother and child for the entire night or part of the night. The analysis was limited to children from single births who were breastfed at 3 months. Multivariate analyses were carried out using Poisson regression.
Of 4231 live births, 2889 were breastfed at age 3 months. The prevalence of BF at age 12 months was 59.2% in the children who bedshared at 3 months and 44% in those who did not (adjusted prevalence ratio [PR] for weaning= 0.75; 95% confidence interval [CI] = 0.69-0.81; P < .001). Among children who were exclusively breastfed at 3 months, 75.1% of those who also bedshared were still breastfed at age 12 months, versus 52.3% of those who did not bedshare (adjusted PR = 0.63; 95% CI = 0.53- 0.75; P < .001). The adjusted PR was 0.74 (95% CI = 0.60-0.90; P = .003) in children who were predominantly breastfed and 0.83 (95% CI = 0.76-0.90; P < .001) in those who were partially breastfed.
Bedsharing at 3 months protected against weaning up to age 12 months.
BF, Breast-feeding; CI, Confidence interval; DLP, Date of last period; IEN, National Economic Indicator (Brazil); LBW, Low birth weight; PR, Prevalence ratio; SIDS, Sudden infant death syndrome
Matijasevich A, Howe LD, Tilling K, Santos IS, Barros AJD, Lawlor DA. Maternal education inequalities in height growth rates in early childhood: 2004 Pelotas birth cohort study. Paediatric and Perinatal Epidemiology 2012; 26: 236–249.
Socio-economic inequalities in attained height have been reported in many countries. The aim of this study was to explore the age at which maternal education inequalities in child height emerge among children from a middle-income country. Using data from the 2004 Pelotas cohort study from Brazil we modelled individual height growth trajectories in 2106 boys and 1947 girls from birth to 4 years using a linear spline mixed-effects model. We examined the associations of maternal education with birth length and trajectories of growth in length/height, and explored the effect of adjusting for a number of potential confounder or mediator factors.
We showed linear and positive associations of maternal education with birth length and length/height growth rates at 0–3 months and 12–29/32 months with very little association at 3–12 months, particularly in boys. By age 4 years the mean height of boys was 101.06 cm (SE = 0.28) in the lowest and 104.20 cm (SE = 0.15) in the highest education category (mean difference 3.14 cm, SE = 0.32, P < 0.001). Among girls the mean height was 100.02 cm (SE = 0.27) and 103.03 cm (SE = 0.15) in the lowest and highest education categories, respectively (mean difference 3.01 cm, SE = 0.31, P < 0.001). For both boys and girls there was on average a 3-cm difference between the extreme education categories. Adjusting for maternal height reduced the observed birth length differences across maternal education categories, but differences in postnatal growth rates persisted.
Our data demonstrate an increase in the absolute and relative inequality in height after birth; inequality increases from approximately 0.2 standard deviations of birth length to approximately 0.7 standard deviations of height at age 4, indicating that height inequality, which was already present at birth, widened through differential growth rates to age 2 years.
childhood height; Pelotas birth cohort; maternal education; child growth
de Moura DR, Costa JC, Santos IS, Barros AJD, Matijasevich A, Halpern R, Dumith S, Karam S, Barros FC. Risk factors for suspected developmental delay at age 2 years in a Brazilian birth cohort. Paediatric and Perinatal Epidemiology 2010; 24: 211–221.
Many children are at risk of not achieving their full potential for development. Epidemiological studies have the advantage of being able to identify a number of associated factors potentially amenable to intervention. Our purpose was to identify risk factors for suspected developmental delay (SDD) at age 2 years among all children born in the city of Pelotas, Brazil, in 2004. This study was part of the 2004 Pelotas Birth Cohort. The Battelle Screening Developmental Inventory (BSDI) was administered to cohort children at age 2 years. A hierarchical model of determination for SDD with confounder adjustment was built including maternal sociodemographic, reproductive and gestational characteristics, as well as child and environmental characteristics. Multivariable analysis was carried out using Poisson regression. Prevalence ratios (PR) and 95% confidence intervals [95% CI] were calculated.
In the results, 3.3% of the 3869 children studied screened positive for SDD. After confounder control, children more likely to show SDD were: those with positive BSDI at age 12 months (PR = 5.51 [3.59, 8.47]); with 5-min Apgar <7 (PR = 3.52 [1.70, 7.27]); with mothers who had <4 years of schooling (PR = 3.35 [1.98, 5.66]); from social classes D and E (PR = 3.00 [1.45, 6.19]); with a history of gestational diabetes (PR = 2.77 [1.34, 5.75]); born <24 months after the last sibling (PR = 2.46 [1.42, 4.27]); were not told child stories in the preceding week (PR 2.28 [1.43, 3.63]); did not have children's literature at home (PR = 2.08 [1.27, 3.39]); with low birthweight (PR = 1.75 [1.00, 3.07]); were born preterm (PR = 1.74 [1.07, 2.81]); with <6 antenatal care appointments (PR = 1.70 [1.07, 2.68]); with history of hospitalisation (PR = 1.65 [1.09, 2.50]); and of male sex (PR = 1.43 [1.00, 2.04]). These risk factors may constitute potential targets for intervention by public policies and may provide help to paediatricians in preventing developmental delay.
child development; Pelotas Birth Cohort; Apgar score; maternal education; social class; maternal gestational diabetes; inter-birth interval; parenting; birthweight; gestation
To investigate the association between bed-sharing with the mother at 3 months of age and incidence of hospitalisation due to pneumonia and diarrhoea between 3 and 12 months.
The 2004 Pelotas Birth Cohort included all live births to mothers living in Pelotas, Brazil, in 2004. Information on bed-sharing was obtained at the 3-month follow-up visit, and on hospitalisations at the 12-month visit, both based on mothers’ reports. Only singleton infants with complete information on hospitalisation were analysed.
3906 infants were included. The bed-sharing prevalence at 3 months was 46.4% (95% CI 44.9 to 48.0%). The incidence of pneumonia admissions between 3 and 12 months was 3.6% (95% CI 3.3 to 4.2%) and diarrhoea, 0.9% (95% CI 0.6 to 1.2%). In crude analyses, bed-sharing with the mother was associated with higher incidence of hospitalisation due to both pneumonia and diarrhoea. There was interaction between bed-sharing and duration of breastfeeding regarding the chance of admission due to pneumonia. Among infants breastfed for 3 months or less, the chance of hospitalisation due to pneumonia among bed-sharers was almost twice as high as among non-bed-sharers (adjusted OR 1.96; 95% CI 1.08 to 3.55). There was no association between bed-sharing and hospitalisation due to pneumonia among infants breastfed for longer than 3 months in crude or adjusted analyses. The association between bed-sharing and admissions due to diarrhoea lost statistical significance after allowing for confounders.
The effect of bed-sharing in infancy on the risk of hospitalisation due to pneumonia depends on breastfeeding, such that weaned children present higher risk.
Breast Feeding; Child Health; Sleep; Epidemiology; Public Health