CCL2 and gestational diabetes: Serum samples collected between 24 and 28 weeks of pregnancy from singleton pregnancies with gestational diabetes mellitus and gestational age-matched normal pregnant women were analyzed by bead-based multiplex assays for chemokine (C-C motif) ligand 2 (CCL2), chemokine (C-C motif) ligand 4 (CCL4), interferon gamma (IFN-γ), C-C motif chemokine ligand 11 (CCL11) and tumor necrosis factor alpha (TNF-α) levels.