Low dose gonadotropin-releasing hormone agonist treatments with early discontinuation for controlled ovarian hyperstimulation in an<Emphasis Type="Italic">in vitro</Emphasis> fertilization program

Aim:  The purpose of the present study was to investigate the applicability of a protocol for controlled ovarian hyperstimulation (COH) featuring early discontinuation of low dose gonadotropin-releasing hormone agonist (GnRHa) for ovulation induction for in vitro fertilization (IVF).
Methods:  Four hundred and eighty-seven women undergoing 555 IVF cycles were recruited into the study. Controlled ovarian hyperstimulation was achieved by using either a short protocol of low dose GnRHa (for 5 days only; groups 1 and 2) or a modified long protocol with early discontinuation of GnRHa (groups 3 and 4). Groups 1 and 3 received urinary follicle-stimulating hormone (FSH) and groups 2 and 4 received recombinant FSH. Oocyte retrieval was performed 34 to 36 h after human chorionic gonadotropin (hCG) injection, followed by embryo transfer 3 days later.
Results:  Luteinizing hormone (LH) levels on the hCG injection day were lower with the modified long protocol (groups 3 and 4) than with the short 5-day treatment (groups 1 and 2). There were higher LH levels in group 1 than in groups 2, 3 and 4, resulting in a worse fertilization rate and clinical pregnancy rate. There were no statistically significant differences between groups 2, 3 and 4 in the rates of fertilization, clinical pregnancy and delivery. A higher estradiol (E₂) level in group 3 than in groups 1, 2 and 4 resulted in a worse implantation rate.
Conclusion:  Early cessation of GnRHa may not induce a premature LH surge in controlled ovarian hyperstimulation, while a low dose also offers a useful alternative to a long protocol of IVF. Ovarian stimulation with recombinant follicle-stimulating hormone (rFSH) is considered to be favorable in this low dose GnRHa treatment. (Reprod Med Biol 2003; 2 : 25–30)