SLC2A1 and obesity due to melanocortin 4 receptor deficiency: Furthermore, in both female and male fetuses, placental expression of glucose transporters (Slc2a1 and Slc2a3) was not compromised by advanced maternal age, unlike other adverse maternal conditions in rodents and women, such as excess glucocorticoids, malnutrition, obesity, hyperglycemia and hypoxia41–47.