Abstract
The hypothesis that low urinary oestriol excretion in pregnancies with fetal Down's syndrome is caused by functionel defects in the fetal hypothalamus, pituitary or adrenal cortex (10) gave rise to investigation of four women with Down's syndrome in order to detect a persistence into adulthood of the possible disturbancies in the function of these endocrine organs. During one menstruel cycle the FSH, LH, estradiol, and progesterone levels in plasma had a normal course, indicating ovulation and formation of a corpus luteum. the serum levels and urinary excretion of corticosteroids and their metabolites were also found normal. the investigation does not support any hypothesis of congenital functional defects in the hypothalamic-pituitary-gonadal system or the adrenal cortical function.