Progesterone adrenal, production

The production of progesterone and oestrogen is important for the first 9-10 weeks of pregnancy. After this, the placenta and also the adrenal cortex of the foetus gradually take over the production of these hormones. 

The interaction between the adrenal cortex of the foetus and the placenta in production of steroid hormones is complex. In outline, the placenta produces progesterone from cholesterol (which is available from the maternal blood) whereas the foetal adrenal cortex produces corticosteroids and androgens from the progesterone produced in the placenta. The placenta then converts some of these androgens into oestrogens. The interplay between the placenta and the foetal adrenal cortex is acknowledged by the use of the term foeto-placental unit to describe steroido-... 

Aldosterone production is initiated by 21-hydroxylation of pregnenolone in the adrenal glomerulosa, where there is no 17-hydroxylase activity. The product of hydroxylation of pregnenolone by P450c21 is 21-hydroxy-progesterone, also known as deoxycorticosterone (DOC). The quantity of aldosterone produced by the adrenal is only 1% of that of cortisol for this reason, not all patients with classic P450c21 deficiency manifest with salt wasting. 

The liver is the most important area for (he production of cholesterol and bile acids. The ovaries are the most important sources of estrogen and progesterone (progesterone is produced in the corpus luteum of the ovary). The testes are the major site of androgen production, testosterone especially. The adrenal cortex produces the mineralocorticoids and glucocorticoids, and the androgens dehydroepiandrosterone and androstenedione. 

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