TFRC and gestational diabetes: ADA = American Diabetes Association; GDM = gestational diabetes mellitus; BMI = body mass index; CRP = C‐reactive protein; WHO = World Health Organization; IADPSG = International Association of Diabetes and Pregnancy Study Groups; sTfR = serum transferrin receptor; TIBC = total iron-binding capacity; PIH = pregnancy-induced hypertension; LDL = low-density lipoprotein.