Serum Progesterone Concentration is Raised during Early Follicular Phase in Women with Polycystic Ovaries

Abstract

Polycystic ovaries (PCO), identified by ultrasonography, may be present in as many as 23% of otherwise normal women not manifesting any of the clinical signs of obesity, hirsutism and oligomenorrhoea.' Furthermore, a third of women being investigated for infertility in a recent study were shown to have PCO by laparocopy.^ Thus this condition would appear to be far more common than hitherto suspected, and could account for a large proportion of infertility cases. The condition is usually associated with elevated concentrations of LH and androgens, including testosterone,' but some indices such as free androgen index may be influenced by factors such as age and obesity4 and LH concentrations are not always raised. The ovaries and the adrenal glands are the main sources of androgens in women. Increased stimulation of the ovaries by LH during the follicular phase could account for raised androgen concentrations, in which case precursor progestogens should also be increased. Late onset congenital adrenal hyperplasia due to mild (subclinical) 2 1 a-hydroxylase deficiency might also result in increased concentrations of progesterone and I7a-hydroxyprogesterone, some of which would be converted to androgens. Since low dose progestogen pills can be used t o reduce fertility in normal women, it is possible that raised endogenous progestogen concentrations in women with PCO during the follicular phase could contribute to their infertility. We have compared serum progesterone, 17ahydroxyprogesterone and various androgen indices during the early part of the follicular phase in women with PCO and in women with normal ovaries, since during this part of the cycle the concentrations of these steroids are normally low. METHODS