This study therefore assesses the adipokines (leptin and adiponectin), inflammatory cytokines (IL-6 and TNF-α) and the serum expression of miRNAs (miR-29a-3p, miR-103a-3p, miR-132-3p and miR-222-3p) at the beginning of gestation (Visit 1, baseline 8–12 GW), at the time of GDM screening (Visit 2: 24–28 GW) and at 2–3 years PD when T2DM is diagnosed (Visit 3). This evidence concerns the gene LEP and type 2 diabetes mellitus.