Gestational diabetes mellitus (GDM) is associated with a number of complications, including developmental disorders in the child but the specific association is unclear. The purpose of this review is to summarize the latest knowledge about the association between GDM and one of the developmental disorders, namely autism spectrum disorder (ASF) in the child. Large cohort studies found that GDM increases the risk of ASF in the child, and that the risk increases the earlier the mother is diagnosed with GDM.