Haematological changes during ovulation-induction by gonadotrophins

The oestrogen response to ovulation-induction by gonadotrophins initiates a preovulation rise in total leucocytes and promotes fluid retention. In consequence of the latter, cyclic changes occur in blood haemoglobin and the haematocrit. The level of oestrone excretion in the follicular phase of induced cycles indicates that multiple follicular development probably occurs, and this also appears to affect the luteal phase. It seems likely, therefore, that the data present a rather exaggerated picture of the situation which obtains in normal menstrual cycles.