Fetoplacental endocrine and metabolic physiology.

This article deals with the formation and metabolism of steroid hormones in pregnancy and the proposed functions of these hormones; the formation of the polypeptide and neuropeptide hormones of fetus and placenta and their regulatory roles in pregnancy homeostasis; and the fetal thyroid gland and its regulation. It also focuses on the role played by the endocrine system in allowing the pregnancy to function as a heterograft and in initiating the process of labor.