LEP and gestational diabetes: WLS analysis showed that leptin upregulation in GDM was closely associated with epigenetic remodeling at specific CpG sites within the LEP promoter, whereas the relationship between promoter demethylation and FBG was altered in GDM.<h4>Conclusion</h4>Decidual LEP promoter demethylation is associated with hyperleptinemia and shows an epigenetic mechanism linking GDM.