The First 1000 Days of Life Factors Associated with Childhood Asthma Symptoms: Brisa Cohort, Brazil

This prospective study used data from the BRISA Cohort, Sao Luis, Brazil (n = 1140) and analyzed associations between environmental factors up to the first 1000 days of life and Childhood Asthma Symptoms. Childhood Asthma Symptoms was a latent variable based on the number of wheezing episodes, emergency care visit due to wheezing, diagnosis of asthma and diagnosis of rhinitis. A theoretical model that included prenatal factors (socioeconomic status, pregestational body mass index-BMI, soft drink and junk food consumption), birth factors (gestational age, smoking and diseases during pregnancy, birth weight and type of delivery), first year of life factors (breastfeeding, environmental aeroallergens and respiratory diseases) and BMI z-score in the second year of life, was analyzed by structural equation modeling. High pregestational BMI, high soft drink consumption, cesarean section without labor, chill in the first three months of life, carpeted floor and child's exposure to tobacco were associated with higher values of Childhood Asthma Symptoms. In contrast, high birth weight, breastfeeding and infant's age were associated with lower values of Childhood Asthma Symptoms. These findings support the hypothesis that environmental factors that are present before conception and up to the first 1000 days of life are associated with asthma.