Association between exposure to air pollution during intrauterine life and cephalic circumference of the newborn.

It has been observed that air pollution can affect newborn health due to the negative effects of pollutants on pregnancy development. However, few studies have evaluated the impact of maternal exposure to urban air pollution on head circumference (HC) at birth. Reduced head growth during pregnancy may be associated with neurocognitive deficits in childhood. The objectives of this study were to evaluate the association between maternal exposure to air pollution and HC at birth and to provide context with a systematic review to investigate this association. This was a prospective study of low-risk pregnant women living in São Paulo, Brazil. Exposure to pollutants, namely, nitrogen dioxide (NO2) and ozone (O3), was measured during each trimester using passive personal samplers. We measured newborn HC until 24 h after birth. We used multiple linear regression models to evaluate the association between pollutants and HC while controlling for known determinants of pregnancy. To perform the systematic review, four different electronic databases were searched through November 2018: CENTRAL, EMBASE, LILACS, and MEDLINE. We selected longitudinal or transversal designs associating air pollution and HC at birth. Two reviewers evaluated the inclusion criteria and risk of bias and extracted data from the included papers. Thirteen studies were selected for the systematic review. We evaluated 391 patients, and we did not observe a significant association between air pollution and HC. Regarding the systematic review, 13 studies were selected for the systematic review, 8 studies showed an inverse association between maternal exposure to pollutants and HC, 4 showed no association, and one observed a direct association. In the city of São Paulo, maternal exposure to pollutants was not significantly associated with HC at birth. The systematic review suggested an inverse association between air pollution and HC at birth.

Short-Term Exposure to Urban Air Pollution and Influences on Placental Vascularization Indexes.

BACKGROUND: It has been widely demonstrated that air pollution can affect human health and that certain pollutant gases lead to adverse obstetric outcomes, such as preeclampsia and fetal growth restriction. OBJECTIVES: We evaluated the influence of individual maternal exposure to air pollution on placental volume and vascularization evaluated in the first trimester of pregnancy. METHODS: This was a cross-sectional study on low-risk pregnant women living in São Paulo, Brazil. The women carried passive personal NO2 and O3 monitors in the week preceding evaluation. We employed the virtual organ computer-aided analysis (VOCAL) technique using three-dimensional power Doppler ultrasound to evaluate placental volume and placental vascular indexes [vascularization index (VI), flow index (FI), and vascularization flow index (VFI)]. We analyzed the influence of pollutant levels on log-transformed placental vascularization and volume using multiple regression models. RESULTS: We evaluated 229 patients. Increased NO2 levels had a significant negative association with log of VI (p = 0.020 and beta = -0.153) and VFI (p = 0.024 and beta = -0.151). NO2 and O3 had no influence on the log of placental volume or FI. CONCLUSIONS: NO2, an estimator of primary air pollutants, was significantly associated with diminished VI and VFI in the first trimester of pregnancy.

Associations of maternal personal exposure to air pollution on fetal weight and fetoplacental Doppler: A prospective cohort study.

We determined the influence of maternal air pollution exposure during each trimester of pregnancy on fetal and birth weight and fetoplacental hemodynamics. In total, 366 women with singleton pregnancies were prospectively followed in the city of São Paulo, Brazil. Nitrogen dioxide (NO2) and ozone (O3) were measured during each trimester using passive personal samplers. We evaluated fetal weight and Doppler velocimetry data from the umbilical, middle cerebral, and uterine arteries in the 3rd trimester, and birth weight. Multivariate analysis was performed, controlling for known determinants of fetal weight. Exposure to higher levels of O3 during the 2nd trimester was associated with higher umbilical artery pulsatility indices (PIs) [p=0.013; beta=0.017: standard error (SE)=0.007]. Exposure to higher levels of O3 during the 3rd trimester was associated with lower umbilical artery PIs (p=0.011; beta=-0.021; SE=0.008). Our results suggest that in the environment of São Paulo, O3 may affects placental vascular resistance.

Weight gain in the first two years of life, asthma and atopy: the SCAALA cohort study.

OBJECTIVE: To evaluate the association between weight gain in the first two years of life and the occurrence of wheezing, asthma, serum IgE, skin reactivity and pulmonary function. DESIGN: Cohort study. SETTING: The metropolitan region of Salvador, Bahia, Brazil. SUBJECTS: The association was studied between 1997 and 2005 in 669 children up to 11 years of age. Data were collected on asthma and risk factors, both current factors and those present in the first years of life. Weight gain was considered fast when the Z-score was >0·67. Poisson regression was used in the multivariate statistical analysis. RESULTS: Wheezing was reported in 25·6 % of the children. Weight gain was considered fast (Z-score >0·67) in 29·6 % of the children and slow (Z-score <-0·67) in 13·9 %. Children in the slow weight gain group had 36 % fewer symptoms of asthma (prevalence ratio = 0·65; 95 % CI 0·42, 0·99). CONCLUSIONS: Slower weight gain in the early years of life may constitute a protective factor against symptoms of asthma. The relevance of this finding for public health is not yet certain, since it is known that children with slow and fast weight gain may be more likely to develop adverse health consequences related to both these situations.

Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil.

OBJECTIVE: To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4-12 years of age living in the city of Salvador in 2005. DESIGN: Cross-sectional study nested in a cohort. SETTING: The metropolitan region of Salvador, Bahia, Brazil. SUBJECTS: The study included 1129 children of 4-12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. Poisson's multivariate regression was adopted. RESULTS: Wheezing was found in 29·1% and asthma in 22·8% of children, both conditions being more common in those under 6 years of age and 34% more common in overweight children (prevalence ratio (PR) = 1·34; 95% CI 1·07, 1·67) following adjustment. The ratio between forced expiratory volume in 1s and forced vital capacity was associated with overweight (PR = 1·35; 95% CI 1·11, 1·61). No statistically significant association was found between overweight and allergen-specific IgE or with wheezing. CONCLUSIONS: These results are in agreement with the hypothesis that overweight is associated with asthma and pulmonary function, even following adjustment for intervening variables known to be associated with the pathogeny of asthma.

Breastfeeding practice in the Brazilian capital cities and the Federal District: current status and advances.

OBJECTIVES: To present the breastfeeding (BF) indicators obtained in the Second Survey on Prevalence of Breastfeeding in the Brazilian Capitals and the Federal District and to analyze their evolution from 1999 to 2008. METHODS: A cross-sectional study was conducted in children younger than 1 year old who participated in the second phase of the multivaccination campaign in 2008. We used two-stage cluster sampling. The questionnaire consisted of closed questions, including data on consumption of breast milk, other types of milk, and other foods on the day prior to the survey. We analyzed the prevalence of BF in the first hour of life; exclusive BF in children younger than 6 months; BF in children aged 9 to 12 months; and medians of exclusive BF and BF. The time variation of BF was established by comparing the medians of exclusive BF and BF in 1999 and 2008. RESULTS: We obtained data from 34,366 children. We found that 67.7% (95%CI 66.7-68.8) of the children were breastfed in the first hour of life; the prevalence of exclusive BF in children aged 0 to 6 months was 41% (95%CI 39.7-42.4), while the prevalence of BF in children aged 9 to 12 months was 58.7% (95%CI 56.8-60.7). There was an increase of 30.7 days in the median duration of exclusive BF and 45.7 days in the median of BF. CONCLUSION: There was a significant improvement in the breastfeeding prevalence in the last decade. However, further efforts are required so that Brazil can reach BF rates compatible with the recommendations of the World Health Organization.

A prática do aleitamento materno nas capitais brasileiras e Distrito Federal: situação atual e avanços / Breastfeeding practice in the Brazilian capital cities and the Federal District: current status and advances

OBJETIVOS: Apresentar os indicadores de aleitamento materno (AM), obtidos na II Pesquisa de Prevalência de Aleitamento Materno nas Capitais Brasileiras e Distrito Federal, bem como analisar sua evolução no período de 1999 a 2008. MÉTODOS: Pesquisa de corte transversal, envolvendo crianças menores de 1 ano de idade que participaram da segunda fase da campanha de multivacinação de 2008. Foram utilizadas amostras por conglomerados, com sorteio em dois estágios. O questionário era composto por questões fechadas, incluindo o consumo de leite materno, outros tipos de leite e outros alimentos no dia anterior à pesquisa. Foram analisadas as prevalências de AM na primeira hora de vida; aleitamento materno exclusivo (AME) em menores de 6 meses; AM em crianças de 9 a 12 meses; e medianas do AME e AM. A variação temporal do AM foi estabelecida por meio da comparação das medianas do AME e AM em 1999 e 2008. RESULTADOS: Obtiveram-se dados de 34.366 crianças. Verificou-se que 67,7 por cento (IC95 por cento 66,7-68,8) mamaram na primeira hora de vida; a prevalência do AME em crianças de 0 a 6 meses foi de 41 por cento (IC95 por cento 39,7-42,4), e do AM em crianças de 9 a 12 meses foi de 58,7 por cento (IC95 por cento 56,8-60,7). Houve aumento de 30,7 dias na duração mediana do AME e de 45,7 dias na mediana do AM. CONCLUSÃO: Houve melhora significativa da situação do AM na última década. Porém, ainda são necessários esforços para que o Brasil atinja índices de AM compatíveis com as recomendações da Organização Mundial da Saúde.

OBJECTIVES: To present the breastfeeding (BF) indicators obtained in the Second Survey on Prevalence of Breastfeeding in the Brazilian Capitals and the Federal District and to analyze their evolution from 1999 to 2008. METHODS: A cross-sectional study was conducted in children younger than 1 year old who participated in the second phase of the multivaccination campaign in 2008. We used two-stage cluster sampling. The questionnaire consisted of closed questions, including data on consumption of breast milk, other types of milk, and other foods on the day prior to the survey. We analyzed the prevalence of BF in the first hour of life; exclusive BF in children younger than 6 months; BF in children aged 9 to 12 months; and medians of exclusive BF and BF. The time variation of BF was established by comparing the medians of exclusive BF and BF in 1999 and 2008. RESULTS: We obtained data from 34,366 children. We found that 67.7 percent (95 percentCI 66.7-68.8) of the children were breastfed in the first hour of life; the prevalence of exclusive BF in children aged 0 to 6 months was 41 percent (95 percentCI 39.7-42.4), while the prevalence of BF in children aged 9 to 12 months was 58.7 percent (95 percentCI 56.8-60.7). There was an increase of 30.7 days in the median duration of exclusive BF and 45.7 days in the median of BF. CONCLUSION: There was a significant improvement in the breastfeeding prevalence in the last decade. However, further efforts are required so that Brazil can reach BF rates compatible with the recommendations of the World Health Organization.