Timing of initiation and dose schedule of leuprolide influence the time course of ovarian suppression.

The time course of suppression of ovarian estrogen production and follicular development with leuprolide was examined in 40 normal women before ovarian stimulation for in vitro fertilization (IVF). Initiation of leuprolide during the midluteal phase caused a significantly more prompt suppression than when treatment was started during the early follicular phase (day 1). Injection of the same total amount of leuprolide in two divided doses also caused a significantly more prompt suppression. These two methods were consistent enough to make routine use of leuprolide practical before ovarian stimulation for IVF.