In the second trimester, the GDM converters had significantly higher fasting and post-load glucose concentration (p < 0.001); higher fasting and post-load insulin concentrations (p < 0.001) except for insulin 30′, as well as higher HOMA-IR (p < 0.001) and HbA1c (p = 0.006). This evidence concerns the gene INS and gestational diabetes.