Nordic databases to evaluate medications in pregnancy.

The objective of this review is to describe the possibilities to assess drugs used in pregnancy by means of the Nordic health registers. The Nordic countries comprise five countries: Denmark, Finland, Iceland, Norway and Sweden and have a total population of 25 million. All five countries have in their national health registers for many years recorded information concerning all births, cancer diagnoses, hospital contacts, causes of death and dispensed drugs. The registers can be used for studying drugs dispensed during pregnancy and though most previous studies focused on risks of congenital abnormalities, other health consequences of maternal medication can also be assessed.