A small proportion of GDM+PCOS+ women in our study required a combination of metformin and insulin (5.4% vs 4.3%), but this is significantly lower compared to 10–44% requirement for supplemental insulin reported by Balani et al. [34] and Rowan et al. [35] On subgroup analysis, GDM+PCOS+ women who were not on metformin had a significantly higher rate of requiring insulin (OR 37.3, p < 0.001) and had higher total insulin requirements at the end of pregnancy (66.9 units vs 26.5 units, p = 0.044). The gene discussed is INS; the disease is polycystic ovary syndrome.