INS and hypothyroidism: 1998; Lanham et al. 2011). Although the thyroid‐deficient ovine fetus had shorter limbs and reduced weights of the heart, lungs and gastrointestinal tract, other tissues such as the kidneys and perirenal adipose tissue were enlarged by hypothyroidism in utero. Before birth, insulin promotes growth of the axial skeleton and tissues such as adipose tissue (Fowden et al. 1989), so increased circulating concentrations of insulin seen in the hypothyroid sheep fetus may contribute to maintenance of vertebral length and tissue‐specific patterns of organ growth.