Multiple linear regression was used to analyze the relationship between iron index and oxidative stress; after BMI correction, the results showed that SF is positively related to MDA, while SOD and GSH are negatively related to SF in GDM group (P < 0.05); the same trend occurred in Control group, but only the relationship of MDA and SF is significantly different (P < 0.05) (Table 4). Here, SOD1 is linked to gestational diabetes.