No significant differences in mRNA levels between the subgroups of GDM-Insulin and GDM-DietmRNA levels of BMAL1, PER3, PPARD and CRY2 genes were significantly ↓ in both GDM subgroups compared to healthy controlsPER3 was significantly negatively correlated with HgbA1CSignificant positive correlation between the expression of BMAL1 versus CRY2,and between BMAL1 versus PPARD. This evidence concerns the gene BMAL1 and gestational diabetes.