As part of the LifeCycle project, the EU Child Cohort Network Variable Catalogue has been developed. The aim of the catalogue is to provide an overview of available data in the EU Child Cohort Network in order to facilitate long-term collaborations between existing pregnancy and child cohorts. The catalogue was build using the MOLGENIS software platform for scientific data (http://molgenis.org, Swertz et al, Bioinformatics, 2014). The catalogue is an openly and accessible online platform that documents what type of harmonized variables (LifeCycle variables) are available from each participating cohort. It also documents how each cohort has harmonized these variables, including the raw variables (source variables) used by the cohorts, which were used to derive the LifeCycle variables. No actual data are contained in the online catalogue. The catalogue also contains a description of each cohort included in the LifeCycle project with links to the code books. Click here to access the catalogue.