Hypersecretion of luteinizing hormone and the polycystic ovary syndrome.

Hypersecretion of luteinizing hormone (LH) is a significant cause of infertility and miscarriage in women with the polycystic ovary syndrome. Many theories have been suggested for the aetiology of pituitary oversecretion of LH. These include increased pulsatility of gonadotrophin releasing hormone (GnRH) hypothalamic dysfunction, altered pituitary sensitivity to GnRH, hyperinsulinaemic stimulation of the pituitary gland and perturbed ovarian-pituitary feedback of steroid hormones. None of these hypotheses fully explain the phenomenon of LH hypersecretion and there has been much debate in the literature on this subject. This paper reviews some of the important clinical studies that have examined the evolving story of hypersecretion of LH and presents in-vivo and in-vitro evidence that suggests that disordered ovarian-pituitary feedback is central to the problem, possibly through a perturbed secretion of nonsteroidal ovarian hormones.