Geração XXI is the first Portuguese birth cohort and intends to characterize prenatal and postnatal development, identifying its determinants in order to understand the state of health in childhood and later in adolescence and adult age.

The recruitment of near 8500 newborns occurred between April 2005 and August 2006 at the five public maternity units in Porto metropolitan area. Except in a subsample – the sub-coorte – for which pregnant women were invited, the mothers were asked to participate after delivery. 

An interviewer collected data on socio-demographics, clinical and reproductive history, prenatal care and about lifestyle and behaviours before and during pregnancy. It was measured parents’ weight and height and detailed anthropometrics were performed on newborns.

The medical registries were assessed and for a subgroup it was collected a blood sample from the mother, father and cord blood.