IGF1 and placental insufficiency: This model is one of placental insufficiency from conception, and results in fetal hypoxaemia, hypoglycaemia, hypoinsulinaemia, hypercortisolaemia, hypothyroidism [reduced thyroid hormones triiodothyronine (T3) and thyroxine (T4)], elevated catecholamines (noradrenaline and adrenaline) and reduced plasma insulin-like growth factor-1 (IGF-1; for review see Morrison, 2008).