In addition to genetic factors, certain potentially modifiable maternal factors, such as type I diabetes mellitus (T1D) in pregnant women, have been shown to be associated with an increased risk of congenital heart disease (CHD) in offspring, but the relationship between gestational diabetes mellitus (GD), maternal overweight, and obesity and offspring developing CHD is unclear, especially for specific CHD subgroups. The study prospectively investigated the association of maternal pregnancy with diabetes mellitus (PGD), GD, overweight, and obesity with the risk of developing CHD in offspring in the same model, while also evaluating its association with specific subgroups of isolated CHD.