Since 2003, novel birth cohorts arose and prevalences of asthma, allergy and eczema have not been studied. Combining these data might lead to better understanding of a.o. the impact of these conditions. The aim of our project is to describe the harmonization process of asthma, allergy, and eczema, and relevant related data. We will perform a meta-analysis using individual participant data of cohorts participating in the EU Child Cohort Network and describe the prevalences of wheezing, asthma, upper and lower respiratory tract infections, lung function values, inhalant allergy, inhalant allergic sensitization, food allergy, food allergic sensitization, itchy rash and eczema measured at each age from birth until adolescence while taking country of cohort and main subject characteristics into account. Additionally,we provide a framework for further research into early life stressors, genetic, epigenetic, and microbiome pathways on the risk of developing respiratory and related outcomes.