Pollen exposure in pregnancy and infancy and risk of asthma hospitalisation - a register based cohort study

Abstract

Background: A seasonal effect of month of birth and risk of allergic disease has been suggested by numerous studies. Few studies have directly measured pollen exposures at different points during pregnancy and in early life, and assessed their effects on risk of respiratory disease outcomes.Methods: Pollen exposure was calculated for the first and last 12 weeks of pregnancy and the first 12 weeks of infancy for all children conceived by women residing in Stockholm, Sweden, between 1988 and 1995. Hospital admission data for respiratory conditions in the first year of life was also collected.Results: Out of 110,381 children, 940 had been hospitalised for asthma by 12-months of age. Pollen leve..