Episodic secretion of hormones and the diagnostic value of single blood estimates. II. Progesterone, oestradiol and oestrone.

The episodic fluctuation of serum progesterone, oestradiol and oestrone levels was studied. Progesterone was determined in the luteal phase, oestradiol and oestrone concentrations were measured in the proliferative and luteal phases in 8 subjects in 10 min intervals between 08 and 12 h a.m. Reliability criteria proved the radioimmunological methods used to be comparable to those employed routinely. The within-person fluctuation of hormone levels characterized by the coefficient of variation of single estimates averaged 20.16, 23.0 and 11.6% for progesterone, oestradiol and oestrone, respectively. The considerable fluctuation of hormone concentrations suggest the importance of hormone measurements to control luteal function and folliculogenesis during the menstrual cycle.