Through FDR correction analysis, the methylation levels at 6 CpG sites within the ARHGAP40, STAT1, C5orf34, RDH12, and YAP1 genes were higher in the GDM group than in the control group, whereas those at 6 CpG sites within the HAPLN3, IFNGR2, YAP1, NFATC4, and DNAJB6 genes were lower in the GDM group than in the control group. Here, HAPLN3 is linked to gestational diabetes.