Serum sex hormone and gonadotropin concentrations in premenopausal women with multiple sclerosis

Dysfunctions within the hypothalamic-pituitary-gonadal axis occur frequently among women with multiple sclerosis (MS) and may induce menstrual disturbances and subsequent infertility. We have measured serum concentrations of prolactin. gonadotropins and sex hormone binding globulin (SHBG) as well as free and bound oestrogen and androgen levels in 14 women of fertile age with MS. These women all displayed regular cycles without having experienced fertility problems. As controls 14 normal women with regular periods and ideal body weight of 91% (range 80-101) were included. Serum from both groups was sampled during the early follicular phase. The MS-patients had significantly (P less than 0.05) higher concentrations of prolactin, LH, FSH, total and free testosterone (P less than 0.01) and a significantly lower serum concentration of oestrone sulphate (P less than 0.01). The abnormal hormone concentrations were not related to clinical status of the disease. We propose that the increased androgen levels are of ovarian origin as adrenal androgens were normal. The reason for the slight increase of prolactin and the marked increase of gonadotropins in women with MS is speculative. As oestradiol levels, however, were within normal range, we assume that a peripheral resistance to gonadotropins combined with an abnormal central regulation causes the increased pituitary secretion.