Resumo em Inglês:

This thematic issue consists of 14 articles derived from studies of the BRISA birth cohort (Ribeirão Preto, State of São Paulo and São Luís, State of Maranhão, northeastern Brazil, a socially and economically less developed region). In these more than 40 years of existence, these cohorts have been able to document the increase in women's education, the improvement of health conditions, the creation of a public Unified Health System (SUS) that provides universal and free access to health care, eradication of hunger, and transition of the nutritional status characterized by a decrease in malnutrition rates and an increase in obesity in Brazil. Particularly in reproductive health, the country experienced a significant drop in fertility, a decrease in maternal and child mortality, and an increase in breastfeeding rates. Universal access to prenatal care and hospital delivery was accompanied by an excessive number of cesareans without clinical indication and early-term births and premature births, largely due to scheduled cesareans. Articles with a longitudinal and transversal methodological approach are presented, using structural equation analysis and propensity score, together with multivariate regressions, which gave a robust analytical treatment to articles in this thematic issue.

Resumo em Inglês:

The objective of this study was to describe the timing of the first dental visit and investigate the association of socioeconomic and behavioral factors with dental visit delay among 10/11-year-old children from two live-birth population cohorts with extremely contrasting socioeconomic profiles. Follow-up data (2004-2005) from cohorts of Ribeirão Preto (RP) (n=790) and São Luís (SL) (n=673) were evaluated. Delay in dental visit was defined as not visiting a dentist before the age of 7. Covariates included family socioeconomic characteristics, mother-related health behavior, and child-related characteristics. Prevalence ratios with robust standard errors were estimated. In both cohorts, less than 5% of children had visited a dentist before the age of two and about 35% of them had not visited a dentist before the age of seven. Lower mother’s schooling and lack of private health insurance were associated with the delay in first dental visit for both cohorts. A small number of mother's prenatal care visits and being from a single-father family or a family without parents were only associated in the RP cohort, while having ≥4 siblings and lifetime dental pain were associated in the SL cohort. The association with dental pain probably reveals a preventive care-seeking behavior. Therefore, the percentage of delayed first dental visit of children was very high even among those with the most educated mothers. Further studies are necessary to analyze recent changes and underlying factors related to access to first dental visit after the implementation of the National Oral Health Policy in 2006.

Resumo em Inglês:

The introduction of early complementary feeding (ECF) is determined by different factors depending on when it occurs. The objective of this study was to analyze factors associated with the introduction of ECF in two different moments of the infant's life: from zero to three and from four to five months of age. A cohort with 3,306 dyads studied in the BRISA survey in São Luis/MA in 2010 was used. Questionnaires were applied at birth and at follow-up when the infants were 15 to 36 months of age of women with more than 20 weeks of gestational age, residing in this municipality. A multivariate model of multinomial logistic regression was used to verify associations between independent variables and ECF at 0 to 3 months and at 4 to 5 months of age. A hierarchical analysis model was used to select variables for confounding adjustment. Variables with a P-value <0.05 were considered significant. For ECF introduced between 0-3 months, the variables “use of pacifier”, “maternal paid activity”, “smoking”, and “postpartum pregnancy” were identified as risk factors. The variables “use of pacifier” and “maternal paid activity” remained associated as a risk for ECF introduced from 4-5 months. The variable ‘mother without partner’ (RR=1.26 and P=0.04) represented a risk factor for ECF only for the 4-5 months period. Although each period presented specific risk factors, the use of pacifier and maternal professional activity were associated in the two periods studied, indicating their importance for the introduction of ECF.

Resumo em Inglês:

Gestational hypertension and pre-eclampsia are important causes of perinatal morbidity. The objective of the present study was to determine the increase in relative risk for developing hypertensive disorders of pregnancy based on the evaluation of pregnant women between 20 and 25 weeks of gestation, and to correlate the findings at this period with the outcome of pregnancy. We conducted a prospective cohort study, with a convenience sample of 1417 patients evaluated at this gestational age, of which 1306 were contacted at childbirth. We detected an increased relative risk of 2.69 (95%CI: 1.86 to 3.89) associated with pulsatility index of the uterine arteries, a 2.8 increase (95%CI: 1.58 to 5.03) in relative risk attributed to maternal age above 35 years, a 1.68 increase (95%CI: 1.17 to 2.40) attributed to parity greater than or equal to 3, and a 5.35 increase (95%CI: 4.18 to 6.85) attributed to chronic hypertension and obesity, with a progressive increase in relative risk according to the degree of overweight, i.e., grades 1, 2, 3, and morbid obesity (2.58, 3.06, 5.84, and 7.28, respectively).

Resumo em Inglês:

The objective of this study was to evaluate the effect of body image dissatisfaction on symptoms of depressive disorder in adolescents. This is a cross-sectional study that included 2,162 adolescents ages 18-19 born in São Luís, Maranhão, Brazil, which was part of the joint RPS cohort (Brazilian birth cohorts of Ribeirão Preto-SP, Pelotas-RS, and São Luís-MA). Socioeconomic characteristics, nutritional status, mental health, and body image characteristics were evaluated. Body image was assessed by Stunkard’s silhouettes scale. The presence of symptoms indicative of depressive disorder was investigated through a diagnostic interview MINI (Mini International Neuropsychiatric Interview). A theoretical model was built in a Directed Acyclic Graph (DAG) in order to investigate the relationship between the variables of the study. The relationship was estimated weighting the inverse probability of selection for the variables of adjustment: sex and nutritional status. Among the dissatisfied adolescents due to overweight, 66.54% were girls, 32.85% were overweight, and 11.99% were obese (P<0.01). There was a significant association between dissatisfaction due to overweight and symptoms of depressive disorder (P=0.01), and there was no evidence of the same association with dissatisfaction due to thinness. Therefore, only dissatisfaction due to overweight was associated with the symptoms of depressive disorder in the evaluated adolescents.

Resumo em Inglês:

During pregnancy, metabolic changes that develop in women may increase the risk of diseases and conditions that may also harm the life of the growing fetus. The aim of the present study was to identify and compare the metabolic profile (MP) during pregnancy in two birth cohorts in 2010 in the cities of Ribeirão Preto (RP) and São Luís (SL), Brazil. Pregnant women (1393 in RP and 1413 in SL) were studied; information was obtained through questionnaires in addition to anthropometric, biochemical, and blood pressure measurements. Data are presented as means and proportions. To compare the characteristics of pregnant women in both cities, chi-squared and Student's t-tests were applied, with 5% significance level. Ribeirão Preto presented higher mean values than SL for pre-gestational body mass index (24.5 vs 23 kg/m2, P<0.001), systolic (108.4 vs 102.8 mmHg, P<0.001) and diastolic (65.9 vs 61.8 mmHg, P<0.001) blood pressure, total cholesterol (226.3 vs 213.7 mg/dL, P<0.001) and fractions, and glycemia (84.5 vs 80.2 mg/dL, P<0.001), except for triglycerides (P=0.135). Women from RP also showed higher rates of pre-gestational overweight and obesity compared with SL (40.1 vs 25.8%). In the present study, pregnant women in RP had a worse gestational metabolic profile than those in SL, with higher pre-gestational excess weight, indicating that nutritional transition was more advanced in the more developed city.

Resumo em Inglês:

Given the increase of women with excess weight or obesity and its possible effects on birth weight, the present study aimed to investigate the association between pregestational maternal body mass index (BMI) and birth weight in a birth cohort from Ribeirão Preto, SP, Brazil. This was a prospective study conducted on 1362 mother-child pairs involving singleton births. The women were evaluated using standardized questionnaires during the second trimester of pregnancy and at the time of childbirth. Information about the newborns was obtained from their medical records. The dependent variable was birth weight, categorized as low, adequate, or high. The independent variable was pregestational maternal BMI, categorized as malnutrition, adequate weight, overweight, and obesity. A multinomial regression model was used to estimate the crude and adjusted relative risk (RR) of low and high birth weight. A high frequency of pregestational excess weight (39.6%) was detected and found to be independently associated with high birth weight (RR=2.13, 95%CI: 1.19-3.80 for overweight and RR=3.34, 95%CI: 1.80-6.19 for obese pregnant women). There was no association between pregestational malnutrition and low birth weight (RR=1.70; 95%CI: 0.81-3.55). The present data showed a high rate of women with excess pregestational weight, supporting the hypothesis that pregestational BMI may contribute to high birth weight babies and indicating the need for actions aiming to prevent excessive weight in women at reproductive age.

Resumo em Inglês:

This study aimed to investigate the association between maternal psychological distress and impairment in mother-child relationship in a sample from a Northeast capital city in Brazil with a low Human Development Index, using directed acyclic graphs (DAG). A total of 3,215 women were evaluated for the presence of psychological distress through the Self Reporting Questionnaire instrument and for the mother-child relationship by the first factor of Postpartum Bonding Questionnaire, considered the most appropriate in the literature. Demographic and socioeconomic variables were used to construct a theoretical model and, after this, multivariate logistic regression was performed using variables suggested by Directed Acyclic Graphs (DAG). Psychological distress was present in 22.7% of the women and 12.6% of them presented impaired mother-child relationships. After adjustment, the variable ‘maternal mental distress' remained associated with impaired mother-child relationship (RR=3.03), and among the explanatory variables only ‘primary school level' (RR=1.48) was associated as a risk factor to this outcome. The results indicated that, in this population, women with psychological distress and lower schooling are more likely to present impaired mother-child relationships.

Resumo em Inglês:

The present study was conducted to evaluate the validity of the Food Frequency Questionnaire (FFQ) used in the RPS Birth Cohort Consortium (Ribeirão Preto, Pelotas, and São Luís) to assess dietary intake of adolescents from São Luís, Maranhão. The research was developed with 152 adolescents aged 18 and 19 years. For the validation of the FFQ, the average of three 24-hour recalls (24HRs) was used as the reference method. The mean and standard deviation of energy and nutrient intake extracted from the surveys were estimated. The paired Student's t-test was used to verify the differences between the instruments. Pearson correlation coefficient, intraclass correlation coefficient (ICC), weighted Kappa, and the Bland-Altman plot were calculated in order to measure the agreement. The study adopted a level of significance <5%. Compared with the three 24HRs, the FFQ overestimated the consumption of most nutrients. Energy-adjusted and de-attenuated concordance Pearson correlation coefficients ranged from 0.06 to 0.43, and correlations were significant for iron, calcium, riboflavin, sodium, saturated fat, niacin, and vitamin C. The energy-adjusted and de-attenuated ICCs ranged from 0.01 to 0.31, and the weighted Kappa ranged from 0.01 to 0.46. The analyses of agreement were significant for vitamin C, fiber, calcium, riboflavin, niacin, sodium, lipids, and iron. In conclusion, the FFQ presented acceptable relative validity for lipids, saturated fatty acids, fiber, calcium, iron, riboflavin, niacin, vitamin C, and sodium. This instrument will be useful in studies about food consumption of adolescents in São Luís, Maranhão.

Resumo em Inglês:

A prospective cohort study was conducted on a convenience sample of 1370 pregnant women with a gestational age of 20 to 25 weeks in the city of Ribeirão Preto. Data on obstetrical history, maternal age, parity, smoking habit, and a history of preterm delivery was collected with the application of a sociodemographic questionnaire. Cervical length was determined by endovaginal ultrasound, and urine and vaginal content samples were obtained to determine urinary tract infection (UTI) and bacterial vaginosis (BV), respectively. The aim of this study was to verify the association of cervical length and genitourinary infections with preterm birth (PTB). Ultrasound showed no association of UTI or BV with short cervical length. PTB rate was 9.63%. Among the women with PTB, 15 showed UTI (RR: 1.55, 95%CI: 0.93–2.58), 19 had BV (RR: 1.22, 95%CI: 0.77–1.94), and one had both UTI and BV (RR: 0.85, 95%CI: 0.13–5.62). Nineteen (14.4%) PTB occurred in women with a cervical length ≤2.5 cm (RR: 2.89, 95%CI: 1.89–4.43). Among the 75 patients with PTB stratified as spontaneous, 10 showed UTI (RR: 2.02, 95%CI: 1.05–3.86) and 14 had a diagnosis of BV (RR: 1.72, 95%CI: 0.97–3.04). A short cervical length between 20 and 25 weeks of pregnancy was associated with PTB, whereas UTI and BV determined at this age were not associated with short cervical length or with PTB, although UTI, even if asymptomatic, was related to spontaneous PTB.

Resumo em Inglês:

Fetuses exposed to alcohol and/or tobacco are at risk for perinatal adversities. However, little is currently known about the association of the separate or concomitant use of alcohol and tobacco with infant motor and cognitive development. Thus, the objective of the present study was to investigate the association between maternal consumption of alcohol and/or tobacco during pregnancy and the motor and cognitive development of children starting from the second year of life. The study included 1006 children of a cohort started during the prenatal period (22-25 weeks of pregnancy), evaluated at birth and reevaluated during the second year of life in 2011/2013. The children were divided into four groups according to the alcohol and/or tobacco consumption reported by their mothers at childbirth: no consumption (NC), separate alcohol consumption (AC), separate tobacco consumption (TC), and concomitant use of both (ACTC). The Bayley Scale of Infant and Toddler Development Third Edition screening tool was used for the assessment of motor and cognitive development. Adjusted Poisson regression models were used to determine the association between groups and delayed development. The results indicated that only the ACTC group showed a higher risk of motor delay, specifically regarding fine motor skills, compared to the NC group (RR=2.81; 95%CI: 1.65; 4.77). Separate alcohol or tobacco consumption was not associated with delayed gross motor or cognitive development. However, the concomitant use of the two substances increased the risk of delayed acquisition of fine motor skills.

Resumo em Inglês:

It is still unknown whether excessive consumption of sugar-sweetened beverages may be linked to gestational hypertensive disorders, other than preeclampsia. This study investigated the association between soft drink consumption and hypertension during pregnancy, analyzing the relationship from the perspective of counterfactual causal theory. Data from pregnant women of the BRISA cohort were analyzed (1,380 in São Luis and 1,370 in Ribeirão Preto, Brazil). The explanatory variable was the frequency of soft drink consumption during pregnancy obtained in a prenatal interview. The outcome was gestational hypertension based on medical diagnosis, at the time of delivery. A theoretical model of the association between soft drink consumption and gestational hypertension was constructed using a directed acyclic graph. Marginal structural models (MSM) weighted by the inverse of the probability of soft drink consumption were also employed. Using Poisson regression analysis, high soft drink consumption (≥7 times/week) was associated with gestational hypertension in São Luís (RR=1.48; 95%CI: 1.03-2.10), in Ribeirão Preto (RR=1.51; 95%CI: 1.13-2.01), and in the two cohorts combined (RR=1.45; 95%CI: 1.16-1.82) compared to lower exposure (<7 times/week). In the MSM, the association between high soft drink consumption and gestational hypertension was observed in Ribeirão Preto (RR=1.63; 95%CI: 1.21-2.19) and in the two cohorts combined (RR=1.51; 95%CI: 1.15-1.97), but not in São Luís (RR=1.26; 95%CI: 0.79-2.00). High soft drink consumption seems to be a risk factor for gestational hypertension, suggesting that it should be discouraged during pregnancy.

Resumo em Inglês:

This study aimed to estimate and compare racial inequality in low birth weight (LBW), preterm birth (PTB), and intrauterine growth restriction (IUGR) in two Brazilian birth cohorts. This was a cross-sectional study nested within two birth cohorts in Ribeirão Preto (RP) and São Luís (SL), whose mothers were interviewed from January to December 2010. In all, 7430 (RP) and 4995 (SL) mothers were interviewed. The maternal skin color was the exposure variable. Associations were adjusted for socioeconomic and biological covariates: maternal education, per capita family income, family economic classification, household head occupation, maternal age, parity, marital status, prenatal care, type of delivery, maternal pre-pregnancy BMI, hypertension, hypertension during pregnancy, and smoking during pregnancy collected from questionnaires applied at birth. Statistical analysis was done with the chi-squared test and logistic regression. In RP, newborns from mothers with black skin color had a higher risk of LBW and IUGR, even after adjusting for socioeconomic and biological variables (P<0.001). In SL, skin color was not a risk factor for LBW (P=0.859), PTB (P=0.220), and IUGR (P=0.062), before or after adjustment for socioeconomic and biological variables. The detection of racial inequality in these perinatal outcomes only in the RP cohort after adjustment for socioeconomic and biological factors may be reflecting the existence of racial discrimination in the RP society. In contrast, the greater miscegenation present in São Luís may be reflecting less racial discrimination of black and brown women in this city.

Resumo em Inglês:

The increasing number of cesarean sections worldwide has encouraged research on the long-term effects of this birth type on the offspring's mental health. The objective of this study was to investigate whether there is an association between birth by cesarean section and the development of mood disorders (depression and bipolar disorders) in adolescents. A cohort study was carried out with 1603 adolescents from 18 to 19 years old who participated in the third phase of a birth cohort study in São Luís, MA, in 2016. Information on birth type and weight, prematurity, mother's age and schooling, parity, marital status, and smoking behavior during pregnancy, were collected at birth. The study outcomes were depression, bipolar disorder, and “mood disorder” construct. A Directed Acyclic Graph (DAG) was developed to select the variables for minimal adjustment for confounding and collision bias. Associations were estimated through propensity score weighting using a two-step estimation model, and confounders for cesarean birth were used in the predictive model. There was no significant association in the relationship between birth type and depression (95%CI: -0.037 to 0.017; P=0.47), bipolar disorder (95%CI: -0.019 to 0.045; P=0.43), and mood disorder (95%CI: -0.033 to 0.042; P=0.80) in adolescents of both sexes. Birth by cesarean section was not associated with the development of mood disorders in adolescents.

Resumo em Inglês:

Intrauterine growth restriction (IUGR) is related to a higher risk of neonatal mortality, minor cognitive deficit, metabolic syndrome, and cardiovascular disease in adulthood. In previous studies, genetic variants in the FTO (fat mass and obesity-associated) and PPARγ (peroxisome proliferator-activated receptor-gamma) genes have been associated with metabolic disease, body mass index, and obesity among other outcomes. We studied the association of selected FTO (rs1421085, rs55682395, rs17817449, rs8043757, rs9926289, and rs9939609) and PPARγ (rs10865710, rs17036263, rs35206526, rs1801282, rs28763894, rs41516544, rs62243567, rs3856806, and rs1805151) single-nucleotide polymorphisms (SNPs) with IUGR, through a case-control study in a cohort of live births that occurred from June 1978 to May 1979 in a Brazilian city. We selected 280 IUGR cases and 256 controls for analysis. Logistic regression was used to jointly analyze the SNPs as well as factors such as maternal smoking, age, and schooling. We found that the PPARγ rs41516544 increased the risk of IUGR for male offspring (OR 27.83, 95%CI 3.65-212.32) as well as for female offspring (OR=8.94, 95%CI: 1.96-40.88). The FTO rs9939609 TA genotype resulted in a reduced susceptibility to IUGR for male offspring only (OR=0.47, 95%CI: 0.26-0.86). In conclusion, we demonstrated that PPARγ SNP had a positive effect and FTO SNP had a negative effect on IUGR occurrence, and these effects were gender-specific.