Luteinizing hormone (LH) surge in patients using buserelin spray during ovarian stimulation for assisted reproduction

The incidence of luteinizing hormone surge was studied in patients who were downregulated with a short protocol of gonadotrophin releasing hormone agonist before ovarian stimulation for assisted reproduction. Buserelin nasal spray 100 micrograms was given 5 times daily from day 2 of the cycle, followed by ovarian stimulation with human menopausal gonadotrophin and follicle stimulating hormone from day 3 onwards. Of the 159 cycles studied, luteinizing hormone surge was detected in 9 cycles (5.7%). The occurrence of LH surge was usually (67%) but not always associated with a fall in serum oestradiol level before administration of human chorionic gonadotrophin. None of the patients developed luteinizing hormone surge after day 10. Even in patients without luteinizing hormone surge the serum luteinizing hormone levels on the day of administration of hCG were significantly higher than those on day 2 before administration of buserelin. It is concluded that a short protocol with intranasal buserelin 500 micrograms per day is inadequate to suppress endogenous luteinizing hormone surge.