In the last decade, many industrialised societies experience massive changes in both the postponement of age at having a first child (tempo) and a drop in the total number of offspring (quantum) (Mills et al 2011). Previous studies suggest that there are genetic influences on fertility behaviour, but specific genetic variants have not yet been identified. The aim of this study is to bridge demographic and genetic research by having ALSPAC participating to the first large scale genome-wide association (GWAS) meta-analysis to identify the novel genes that influence the tempo (age at first birth, AFB) and quantum (number of children ever born, NEB) of human fertility.