Association of breastfeeding with thyroid function and autoimmunity in postmenopausal women.

The present study showed that prolonged breastfeeding was inversely associated with TSH and the prevalence of hypothyroidism. Moreover, TPOAb and the prevalence of TPOAb positivity were inversely associated with number of breastfed children. These results indicate that breastfeeding may exert a protective effect on thyroid function and autoimmunity.