(A) Schematic of the maternal diet regimen. C57BL/6 female mice were fed chow diet (chow group), HFD (GDM group), or HFD supplemented with HFDF (GDM + HFDF group) during pregestation (before mating, 28 days) and postgestation (E0.5 to E18.5, 18 days) (n = 10 mice per group). (B) Blood glucose 2 hours after feeding at different treatment stages (n = 6 mice per group). (C) Serum HbA1c level at E18.5 (n = 6 mice per group). (D) GTT and area under the curve (AUC) at E16.5 (n = 6 mice per group). (E) The stimulation index of insulin release from isolated pancreatic islets of mice at E18.5 (n = 6 mice per group). (F) Serum insulin level (n = 6 mice per group). (G) ITT and AUC (n = 6 mice per group). (H) HOME-IR index (n = 6 mice per group). HOME-IR = [fasting insulin (mIU/liter) × fasting glucose (mM) / 22. 5]. (I and J) Rates of embryo resorption and abnormal fetuses at E18.5 in each group (n = 10 litters per group). (K) Serum TNF-α level at E18.5 (n = 6 mice per group). (L) Two-tailed Pearson’s correlation coefficient analysis of serum TNF-α levels and HOME-IR at E18.5 in mice. Results represent two independent experiments. Data were analyzed by two-way analysis of variance (ANOVA) followed by post hoc Bonferroni tests (B, D, and G), one-way ANOVA followed by post hoc Tukey’s tests [(C), (E), (F), (H), and (K)], and chi-square test [(I) and (J)] and represented the means ± SEM. * or #P < 0.05, ** or ##P < 0.01, and *** or ###P < 0.001, relative to chow and GDM groups, respectively.