Endocrine Changes during Pregnancy in a Patient with Homozygous Familial Hypobetalipoproteinemia

HUMAN pregnancy is characterized by the production of massive quantities of progesterone, which is supplied primarily by the placenta during the second and third trimesters, and of estrogens, which are formed in the placenta from steroid prehormones synthesized principally in the fetal, but also in the maternal, adrenal cortexes. The cholesterol carried in low-density lipoproteins (LDLs) serves an important role in steroidogenesis by supplying substrate for steroid-hormone formation in a number of tissues.^{1 2 3 4 5 6 7 8} On the basis of the available evidence, it seems likely that plasma LDL cholesterol is the major precursor of both progesterone and estrogens during normal human pregnancy.