Because the progressive metabolic derangement of glucose tolerance during GDM mimics the pathogenesis of type 2 diabetes, these data suggest a relationship between reduced glucose effectiveness, reduced insulin sensitivity and reduced erythrocyte deformability accompanying the shift from unsaturated to saturated fatty acids in erythrocyte membrane phospholipids, features already present during the prediabetic stage. Here, INS is linked to type 2 diabetes mellitus.