COMPARISON OF GONADOTROPIN-RELEASING-HORMONE ANALOGS AND HUMAN CHORIONIC-GONADOTROPIN FOR THE INDUCTION OF OVULATION AND PREVENTION OF OVARIAN HYPERSTIMULATION SYNDROME - A CASE-CONTROL STUDY

Gonadotrophin-releasing hormone analogue (GnRHa) has been suggested as an alternative to human chorionic gonadotrophin (HCG) for triggering ovulation, while preventing ovarian hyperstimulation syndrome (OHSS). Since a prospective, controlled study would be unethical at this point , we used a retrospective, case-self control approach to compare GnRHa with HCG in that context, A group of 16 in-vitro fertilization (IVF) patients who had severe OHSS in previous cycles, in which HCG was give n to trigger ovulation, were studied in subsequent cycles in which GnR Ha was used, Each GnRHa cycle (case) was compared to a previous HCG cy cle that resulted in OHSS (self control), None of these subsequent cyc les resulted in severe OHSS. The use of GnRHa did not affect the numbe r of oocytes retrieved or their quality. Serum oestradiol concentratio ns on the day of ovulation triggering were significantly (P < 0.01) hi gher in the GnRHa cycles compared to HCG cycles, Exogenous progesteron e and oestradiol were effective in maintaining relatively constant ser um oestradiol and progesterone serum concentrations during the luteal phase, Pregnancy rate per cycle was similar in the two groups, In conc lusion, the use of GnRHa to induce ovulation in IVF patients, who are at high risk for developing OHSS, effectively eliminates this risk wit hout affecting other parameters of the stimulation cycle.