Effect of a lower-dose cetrorelix acetate protocol on in-vitro fertilization outcome.

Objective: To determine whether a low initial dosage of cetrorelix acetate could prevent a premature luteinizing hormone (LH) surge in women undergoing controlled ovarian stimulation.

Method: Treatment with a recombinant follicle stimulating hormone was started on Day 3 of the menstrual cycle, and 0.125 mg of cetrorelix was injected daily from Day 5 of the ovarian stimulation until the diameter of the dominant follicle reached at least 16 mm. The dosage was then doubled and maintained at 0.250 mg/day until the day before the injection of human chorionic gonadotropin.

Result: There was a significant decrease in serum LH concentration 1 day after doubling the cetrorelix dosage, and the LH concentration remained low during the follicular phase. Clinical pregnancy occurred in 18 women (42.8%), with 2 intrauterine fetal deaths before the 12th week.

Conclusion: Increasing the cetrorelix dosage from 0.125 to 0.250 mg/day when the follicular size is appropriate can prevent a premature LH surge.