IGF2 and gestational diabetes: Unlike the methylation level of IGF2, increased methylation level at CpG sites 2,3,5,7,8,11~12,14,15~16,19~22,23,24,25 and 29 of H19 DMR was found in GDM group compared to NGT group, and the else 12 sites of H19 DMR was shown lower methylation level in GDM group compared to the NGT group.