Strengths and weaknesses of the study
Strengths of this study include that it is general population
based and that the national health registers used have been
validated and have good coverage, the data were collected
prospectively and the recording of exposures was not influenced
by the outcome. Importantly, it was possible to
adjust for maternal characteristics to confirm that the association
of GDM with CVD is independent of other CVD
risk factors. The matching criteria were used to take into
account potential variation for local strategies for screening
and diagnosis of GDM or variation in recording of maternal
characteristics or disease risk. During the period 1991