Abstract: Objective To investigate the interaction and predictive value of peroxisome proliferator-activated receptor-γ-coactivator 1α (PGC-1α) and micrornA-222-3p (miR-222-3p) in susceptibility to gestational diabetes mellitus (GDM).Methods A total of 136 pregnant women at high risk of GDM who were registered in the Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine from January 2021 to May 2022 were selected as the subjects. The levels of serum PGC-1α and miR-222-3p were detected at 12 to 13 weeks' gestation. Then, 75 g glucose glucose tolerance test (OGTT) was performed at 24 to 28 weeks' gestation. The fasting insulin (FINS), glycocated hemoglobin (HbA1c) and blood lipid were detected, while the insulin resistance index (HOMA-IR) was calculated. According to OGTT results, the pregnant women were divided into two groups: a normal group and a GDM group. The two groups were compared for clinical data, glycolipid metabolism indexes, serum PGC-1α and miR-222-3p levels. Pearson correlation coefficient was used to analyze the correlation between serum PGC-1α and miR-222-3p levels and glycolipid metabolism indexes. The independent relationship between PGC-1α, miR-222-3p and GDM and their interaction in susceptibility to GDM were analyzed. A receiver operating characteristic curve (ROC curve) was plotted to evaluate the predictive value of serum PGC-1α and miR-222-3p levels for GDM.Results Compared with the normal group, the GDM group showed increases in age, prepregnancy body mass index, history of GDM, prepregnancy proportion of polycystic ovary syndrome, fasting blood glucose (FPG), 1 h postprandial blood glucose (1 h PG), 2 h postprandial blood glucose threshold (2 h PG), FINS, HOMA-IR, HbA1c, triglyceride (TG), total cholesterol (TC) and miR-222-3p, as well as decreases in PGC-1α (P<0.05). Serum PGC-1α level was negatively correlated with FPG, FINS and HOMA-IR, while miR-222-3p level was positively correlated with FPG, FINS and HOMA-IR (P<0.05). The AUC value of GDM assessed by PGC-1α and miR-222-3p was higher than that assessed by them alone (Z statistics/P=3.504/0.001, 2.467/0.014). After adjusting for confounding factors, PGC-1α and miR-222-3p were still independently correlated with the occurrence of GDM (P<0.05). PGC-1α and miR-222-3p had antagonistic effect on GDM susceptibility, and 41.0% of GDM susceptibility co-existed between PGC-1α and miR-222-3p was caused by their interaction.Conclusions PGC-1α and miR-222-3p have antagonistic effect on susceptibility to GDM, and their combination is significant for improving the predictive value of GDM.