Results: During COVID-19, the rate of positive GDM tests approximately halved (20% (42/210) in 2020 vs. 42.2% (92/218) in 2019, (p < 0.01)) with higher rates of requirement for insulin at diagnosis (21.4% (2020) vs. 2.2% (2019); p < 0.01), and at term (31% (2020) vs. 5.4% (2019); p < 0.01). This evidence concerns the gene INS and gestational diabetes.