Data pooled from four studies [36, 37, 47, 48] that compared GDM women with non-GDM groups showed no statistically significant difference in transferrin (TRF) levels −0.25 ng/mL (95% CI: −1.14 to 0.63; I2 = 94.7%, p < 0.001) (Figure 7). The gene discussed is TF; the disease is gestational diabetes.