GDF15 and gestational diabetes: The area under the preterm delivery ROC curve was 0.784 in non-GDM and the area under the macrosomia ROC curve was 0.787 in GDM (Figure 1E and F; Supplementary Tables S12 and S13), supporting that serum GDF15 level in second trimester can improve the predictive efficiency of common indicators for preterm delivery in non-GDM and macrosomia in GDM.