Subjects will return to the clinic on Stimulation Days 3 or 4 and 6 or 7 (note: Stimulation Day 1 equals the first day of study drug) for blood sampling and ultrasounds. Ultrasound and serum monitoring will be repeated every 2 days thereafter until a lead follicle reaches a mean diameter of ³ 14 mm, and then daily until an LH surge occurs. Monitoring will be discontinued if a lead follicle ³ 14 mm has not developed by Stim Day 18 of the cycle (inadequate treatment cycle) with a serum progesterone being obtained one week after discontinuing monitoring.