Insulin influences on fetal growth.

Insulin appears to function as a "growth hormone" during late fetal development in man and other species. Infants of diabetic mothers exhibit generalized somatic hypertrophy except for the brain. Effects of insulin on fetal growth may be direct influences on cell proliferation or insulin may indirectly affect growth through stimulation of glucose and amino acid uptake into fetal tissues. While hyperinsulinism results in fetal macrosomy there is a delay in pulmonary functional maturity in infants of diabetic mothers that may reflect insulin induced alterations in lung growth and substrate flow in phospholipids.