Considering the necessity of insulin therapy in the GDM group, women with the TT genotype were more likely to develop insulin-dependent diabetes (45.5%) compared to other genotypes ((22.7%—CC genotype, 31.8%—CT genotype) OR 5.67 [CI 95% 1.61–19.97], p = 0.005) (Table 4). The gene discussed is INS; the disease is type 1 diabetes mellitus.