INS and obesity due to melanocortin 4 receptor deficiency: Studies have demonstrated that some factors are underlying the requirement of insulin therapy for glycemic control in pregnancies complicated by GDM, such as diagnosis of GDM at an early gestational age, obesity, family history of diabetes, exacerbated fetal growth, fasting glucose levels, the values of the abnormal blood glucose level of 75 g oral glucose tolerance tests (OGTT), and the value of glycated hemoglobin [2].