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. The gene discussed is INS; the disease is gestational diabetes.