Premium
Endocrinology of the Conceptus
Author(s) -
France John T.
Publication year - 1970
Publication title -
australian and new zealand journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.734
H-Index - 65
eISSN - 1479-828X
pISSN - 0004-8666
DOI - 10.1111/j.1479-828x.1970.tb00418.x
Subject(s) - placenta , conceptus , dehydroepiandrosterone , fetus , endocrinology , medicine , hormone , steroid , endocrine system , pregnanediol , biology , pregnancy , androgen , genetics
Summary Steroid metabolism in pregnancy involves complex inter‐relationships between fetus, placenta and mother. Evidence indicates that the placenta lacks certain enzymes that are necessary for the biosynthesis of steroid hormones. The fetus possesses these enzymes, but on the other hand lacks those enzymes which are present in the placenta. The placenta and fetus are then themselves not complete endocrine organs, but together complement each other, forming a functional unit for the production of steroids. Thus, progesterone is produced in the placenta mainly from maternal cholesterol. Oestrogen production takes place in the fetal‐placental unit. The placenta converts dehydroepiandrosterone sulphate and 16α‐hydroxydehydro‐epiandrosterone sulphate of fetal origin into oestrone/oestradiol and oestriol respectively. Dehydroepiandrosterone sulphate secreted by the maternal adrenal can also be utilised by the placenta for oestrogen biosynthesis. About 50% of the oestrone and oestradiol produced arises from this source.