The Interplay of Cesarean-Section Delivery and First-Birth Order as Risk Factors in Acute Lymphoblastic Leukemia.

BACKGROUND: Childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has been associated with early-life exposures, including birth by cesarean section (C-section), and a deficit of social exposure (first child). These exposures as proxies for microbiome acquisition in infancy are essential to prime the immune system and restrain later dysregulated immune responses that can trigger ALL in susceptible individuals. We tested risk factors pertaining to immune stimulation that may impact BCP-ALL development. METHODS: Cases comprised 1,126 children (0-12 years) with ALL (BCP-ALL: 78.5%) from the EMiLI study group in Brazil (2002-2020). Age- and sex-matched controls (n = 2,252) were randomly selected from healthy children whose mothers participated in the National Placental and Umbilical Cord Blood Bank donation. Multiple logistic regression was run fitted and adjusted for selected covariates models. RESULTS: C-section delivery was associated with increased risk for ALL [odds ratio (OR) ALL: 1.10; 95% confidence intervals (CI), 1.04-1.15; ORBCP-ALL: 1.09; 95% CI, 1.03-1.14], as well as being the firstborn child. Interaction analysis showed a significant effect of first birth on the observed C-section associations (P < 0.0001). Indeed, high-risk children, namely, firstborn children delivered via C-section were at increased risk for ALL (OR: 2.33; 95% CI, 2.40-4.84) compared with non-first, vaginally born children. An increased risk was found for firstborn children delivered by C-section and non-breastfed with ALL (ORALL: 2.32; 95% CI, 1.27-4.24; ORBCP-ALL: 2.37; 95% CI, 1.18-4.76). CONCLUSIONS: Our observations are in accord with the prediction that exposures determining microbiome composition and adrenal pathway in infancy contribute to the risk of BCP-ALL. IMPACT: These findings encourage the exploration of potential preventive interventions. See related commentary by Wiemels and Gallant, p. 292.

Factors Associated with the Lifestyle of Pediatric Healthcare Professionals during the COVID-19 Pandemic.

The objective of this study was to analyze the association between sociodemographic and occupational variables with the lifestyle of health professionals in pediatric units during the COVID-19 pandemic. A cross-sectional study was conducted with 407 health professionals working in four pediatric health units in the State of Bahia, northeast Brazil. The Fantastic Lifestyle Questionnaire and a questionnaire with sociodemographic and employment variables self-applied via Google Forms were used. The final binary logistic regression models revealed significant associations between those who received 3 to 5 minimum wages, without a marital relationship and with more than one employment relationship. Data suggest that these sociodemographic and occupational profiles are more exposed to risky lifestyle behaviors. The findings of this study demonstrated the need for greater attention to the health of health professionals in the pediatric field, as well as the promotion of initiatives that seek to value the work of these professionals and reduce the damage caused to their lifestyle, especially in a pandemic scenario.

Caesarean sections, prenatal and postnatal conditions and childhood acute lymphoblastic leukaemia: A case-control study in the State of São Paulo, Brazil.

INTRODUCTION: Brazil has high rates of caesarean sections, which has been suggested as a risk factor for acute lymphoblastic leukaemia (ALL). In addition, some pre- and postnatal conditions have been identified as relevant in the etiology of ALL. OBJECTIVES: Investigate the association of caesarean sections, pre- and postnatal conditions with childhood ALL in the State of São Paulo. METHODS: Population-based case-control study including children that are below10 years old. Information on study variables was obtained through face to face interviews, through a questionnaire, and the State of São Paulo Declarations of Live Births database. The conditional and unconditional logistic regression approaches were used to calculate the odds ratio (OR) of the associations between caesarean sections, pre- and postnatal conditions with ALL, and 95 % confidence intervals (95 % CI). RESULTS: We observed a weak and non-statistically significant risk for ALL among children exposed to caesarean sections (unconditional logistic regression OR 1.08; 95 % CI 0.70-1.66; conditional logistic regression OR 1.21; 95 % CI 0.72-2.02), but among children under 3 years old and born through a caesarean sections, the risk of ALL was greater (unconditional logistic regression OR 1.70; 95 % CI 0.69-4.21). A negative association for ALL was observed among children with mothers who reported 12 years of schooling or more (unconditional logistic regression OR 0.34; 95 % CI 0.16-0.69). CONCLUSIONS: We found a tenuous suggestive association between caesarean sections and childhood ALL. The mother's high level of education showed an inverse association with ALL.

Cesariana, condições pré-natal e pós-natal e leucemia linfoblástica aguda na infância / Cesarean section, prenatal and post-natal conditions and acute lymphoblastic leukemia in childhood

Introdução: A leucemia linfoblástica aguda (LLA) é a neoplasia pediátrica com maior incidência no mundo. Sua etiologia é resultante de múltiplas interações entre herança genética e exposição a agentes ambientais potencialmente carcinogênicos nos períodos pré-natal, nascimento e pós-natal. O parto cesáreo tem sido apontado como fator de risco para LLA em crianças. No Brasil, país com altas taxas de cesariana, são poucos os estudos que avaliaram a associação de cesariana com LLA na infância. Objetivos: Investigar a associação de cesariana e condições pré-natal e pós-natal com LLA em crianças nascidas no estado de São Paulo. Métodos: Estudo caso-controle de base populacional. Os casos de LLA, crianças nascidas no estado de São Paulo a partir de 1999, foram recrutados em oito hospitais de 2003 a 2009. Os controles foram emparelhados com os casos por sexo, idade e cidade de nascimento. As informações utilizadas nesse estudo foram obtidas em entrevistas com as mães ou responsáveis pelas crianças por meio de questionário estruturado. Informações adicionais foram adquiridas no banco de Declarações de Nascidos Vivos (DNV), que integra o Sistema de Informações de Nascidos Vivos (SINASC) da Secretaria Municipal de Saúde de São Paulo e do Ministério da Saúde. Após o linkage probabilístico dos bancos de dados, a amostra final comporta 133 casos e 459 controles, relação de 3,4 controles por caso. Análises de regressão logística não condicional e condicional foram conduzidas para estimar a associação entre cesariana, condições pré-natal e pós-natal e LLA, com estimava dos odds ratios (OR) e respectivos intervalos de 95% de confiança (IC 95%). Três modelos de regressão logística foram elaborados: 1) ajuste por idade e sexo da criança, idade e escolaridade da mãe; 2) ajuste pelas variáveis anteriores, mais raça e número de consultas; 3) ajuste por todas as variáveis anteriores e a inclusão de idade e a inclusão de idade gestacional e peso ao nascer. Resultados: A análise de regressão logística não condicional, com base no Modelo 2, revelou discreto risco de LLA na exposição à cesariana (OR=1,10; IC95% 0,71-1,70), proteção na condição de mãe com 12 ou mais anos de escolaridade (OR=0,46; IC95% 0,24-0,89) e idade da criança de 6 a 8 anos no diagnóstico (OR=0,30; IC95% 0,13-0,67). Resultados similares foram observados na análise de regressão logística condicional no Modelo 2: cesariana (OR=1,18; IC95% 0,69-2,00), mães com 12 ou mais anos de escolaridade (OR=0,56; IC95% 0,25-1,24). Conclusões: Há uma tênue associação entre cesariana e LLA na infância, sem significância estatística. Alta escolaridade da mãe e crianças na faixa etária entre 6 e 8 anos foram fatores de proteção para LLA. Crianças com síndrome de Down apresentaram seis vezes o risco de LLA. Os resultados obtidos por análise regressão logística condicional foram similares aos da regressão logística não condicional.

Introduction: Acute lymphoblastic leukemia (ALL) is the most common pediatric neoplasia worldwide. Its etiology results from multiple interactions between genetic inheritance and exposure to potentially carcinogenic environmental agents during the prenatal, birth, and postnatal periods. Cesarean section has been identified as a risk factor for ALL in children. In Brazil, a country with high Cesarean section rates, few studies have evaluated the association of Cesarean section with ALL in childhood. Objectives: To investigate the association of Cesarean section, prenatal and postnatal conditions with ALL in children born in the state of São Paulo. Methods: Population-based case-control study. The cases of ALL, children born in the state of São Paulo from 1999, were recruited in eight hospitals from 2003 to 2009. Controls were matched with cases by sex, age and city of birth. The information used in this study were obtained through interviews with mothers or guardians of the children, using a structured questionnaire. Additional information were get from the Live Births Database, stored in the Live Birth Information System at the São Paulo Municipal Health Department and at the Brazilian Ministry of Health. After the databases probabilistic linkage, the final sample entails 133 cases and 459 controls, 3.4 controls per case ratio. Non-conditional and conditional logistic regression analyzes were conducted to estimate the association between cesarean section, pre- and postnatal conditions, and ALL with estimation of odds ratios (OR) and respective 95% confidence intervals (95% CI). Three models of logistic regression were elaborated: 1) adjustment by age and sex of the child, age and schooling of the mother; 2) adjustment for the previous variables, more race and number of queries; 3) adjustment for all previous variables and the inclusion of gestational age and birth weight. Results: The nonconditional logistic regression analysis, based on Model 2, revealed a slight risk of ALL on cesarean section exposure (OR = 1.10, 95% CI 0.71-1.70), protection on the condition of mothers with 12 or more years of schooling (OR = 0.46, 95% CI 0.24-0.89), and age of child from 6 to 8 years at diagnosis (OR = 0.30, 95% CI, 0.13-0, 67). In the conditional logistic regression analysis in Model 2, similar results were observed: cesarean (OR = 1.18, 95% CI 0.69-2.00), mothers with 12 or more years of schooling (OR = 0.56, 95% CI, 0.25-1.24). Conclusions: There is a weak association between cesarean section and ALL in childhood, with no statistical significance. Mother with high education level and children in the age range between 6 and 8 years were protective factors for ALL. Children with Down syndrome had a six-fold risk of ALL. The results obtained by conditional logistic regression analysis were similar to those of non-conditional logistic regression