By overlapping the sequencing results of the methylome and transcriptome, we identified genes such as Shank2, Ank1, Sez6l and Sema5b, which were differentially methylated and expressed in the fetal hippocampus of GDM as factors that may contribute to the cognitive deficits caused by intrauterine hyperglycemia. The gene discussed is ANK1; the disease is Cognitive impairment.