The pregnancy rate was found to be higher when GnRHa was used in a long protocol as compared to a short or ultrashort protocol. There was no evidence of a difference in live birth rate, but this outcome was only reported by three studies. There was no evidence of a difference in the outcomes amongst various long protocols; nor that stopping or reducing GnRHa at the start of stimulation was associated with a reduced pregnancy rate. For all comparison, except a long versus short protocol, there was a lack of power.
Hormonal changes induced by short-term administration of gonadotropin-releasing hormone agonist during ovarian hyperstimulation for in vitro fertilization and their consequences for embryo development.
Several regimens have been developed to administer gonadotropin-releasing hormone agonists in association with human menopausal gonadotropins (hMG) during follicular growth stimulation for in vitro fertilization. The aim of this study was to characterize hormonal changes induced by short-term administration of agonist, and to evaluate a putative impact of the flare-up effect on follicular recruitment and subsequent IVF. Eighteen highly selected patients were randomely divided in two groups. Nine patients received a short-term administration of Buserelin (Hoechst, AG, Franfurt/Main, FRG) (day 1). They were compared with 9 patients who were exposed to a long-term protocol (day 21), and 13 control patients. Agonist-induced luteinizing hormone (LH) and follicle-stimulating hormone (FSH) increase, in early follicular phase, stimulated follicular growth, shortened follicular phase, and induced a transient rise in progesterone. This was followed by a phase of reduced LH secretion associated with a significant modification of LH immunoreactivity. The short-term regimen did not improve the follicular recruitment, and appeared to reduce the oocytes fertilization rate and embryo quality when compared with prolonged administration of peptide.