Abstract:To investigate the relationship between gene polymorphism and insulin resis-tance in patients with gestational diabetes mellitus (GDM). Methods Totally 164 GDM patients and 130 normal pregnant women with impaired glucose tolerance were selected. The genotype was detected by poly-merase chain reaction-restriction fragment length polymorphism and then the clinical data were analyzed. Results There was significant difference between the GA and GG genotypes of (rs4788102) in the GDM group [OR = 1.531, (95% CI: 1.093, 2.374), = 0.04]. There was significant difference in the A allele frequency and the G allele frequency in the GDM group [OR = 1.436, (95% CI: 1.091, 1.972), = 0.01]. In the GDM group, the GA and AA genotypes were significantly different from the GG genotype [OR = 1.699,(95% CI: 1.185, 2.479), = 0.02]. BMI, TG, leptin, and HOMA-IR were significantly different between the GDM patients with AA or GA genotype and those with GG genotype ( P< 0.05). Logistic regression analysis showed that GA and AA genotypes were the risk factors for HOMA -IR elevation. Conclusions (rs4788102) gene polymorphism may be a susceptible locus of GDM, which could be used to predict the risk of GDM in pregnant women.