Conversely, an abundance of IGF-2 leads to macrosomia and generalized organomegaly in infants.34 Although pituitary-derived GH is the main regulator of IGF synthesis in humans, during pregnancy, the regulation of maternal IGFs is controlled by PGH.35 In the fetus and newborn, nutrition increases the insulin-stimulated production of IGFs, serving as the main regulator of growth until the GH-axis has matured.14,15,27,28,40. The gene discussed is INS; the disease is Large for gestational age.