The population-based cohort study examined all 2,432,000 livebirth children without congenital heart disease born in Denmark between 1977 and 2016. Follow-up with the participants began at birth up to the first diagnosis of CVD, death, emigration, or through the end of the study (December 31, 2016).
The authors examined associations between types of maternal diabetes and early onset of CVD in offspring and the combined effect of maternal diabetes and maternal history of CVD on the rate of early-onset CVD in offspring. They also looked at whether pregestational complications of diabetes further increased risk of CVD in offspring. They hypothesized that intrauterine exposure to maternal diabetes could lead to an excess risk of early-onset CVD in offspring from childhood to early adulthood (up to 40 years).
The authors considered offspring born to mothers diagnosed with diabetes before childbirth to have been prenatally exposed to maternal diabetes mellitus. Maternal diabetes was categorized as gestational diabetes or pregestational diabetes. Women with pregestational diabetic complications were classified into two groups: those with one complication and those with multiple complications. The outcome of interest was early-onset CVD in offspring, defined as the first occurrence of CVD in the Danish Register of Cause of Death. The authors identified the outcomes using ICD-8 and ICD-10 codes for CVD or surgery codes for coronary artery bypass graft surgery and percutaneous coronary interventions.