The placenta is a fetal organ located at the interface between mother and fetus. Therefore, the placenta is susceptible to maternal and fetal derangements. In gestational diabetes, various hormones, growth factors, cytokines and metabolites have altered levels in the maternal, the fetal compartment and the placenta. Prominent determinants of placental and fetal growth and development are insulin and the insulin-like growth factors (IGF) 1 and 2. Their levels in the maternal and/or fetal circulation are altered resulting from gestational diabetes. This article will describe placental changes in gestational diabetes and discuss the role of insulin, IGF1 and IGF2 therein.