Thyroglobulin present in fetal serum.
Howdeshell KL. 2002. A model of the development of the brain as a construct of the thyroid system. Environ Health Perspect 110 (suppl 3):337-348.
Serum thyroxine, thyroid-stimulating hormone and thyroxine-binding globulin detected.
Greenberg AH, Czernichow P, Reba RC, Tyson J, Blizzard RM. 1970 Oct. Observations on the maturation of thyroid function in early fetal life. J Clin Invest 49(10):1790-803.
Somatotropes (which produce GH) present.
Sadler TW. 2000. Susceptible periods during embryogenesis of the heart and endocrine glands. Environ Health Perspect 108 (suppl 3):555-561.
Portal system to pituitary established.
Thliveris JA, Currie RW. 1980. Observations on the hypothalamo-hypophyseal portal vasculature in the developing human fetus. Am J Anat 157(4):441-444.