Data resources

We use data from national health registries, national quality registries and other nationwide databases in Denmark, Finland, Norway and Sweden.

These data have been linked at an individual level using the unique national identity number assigned to each resident in the Nordic countries. The identity numbers have been replaced with study numbers in the dataset, and no researcher has access to them.

The CoNARTaS cohort consists of around 7 850 000 children, hereby 170 000 children conceived by ART, as well as their mothers (4 130 000 mothers in total and 127 000 mothers after ART) in Denmark (1994–2014), Finland (1990– 2014), Norway (1984–2015), and Sweden (1985–2015).