Induction of the endogenous gonadotrophin surge for oocyte maturation with intra-nasal gonadotrophin-releasing hormone analogue (buserelin): effective minimal dose

From 1985-1987, a total of 34 couples undergoing superovulation for asingle in-vitro fertilization (IVF) cycle with clomiphene citrate andpurified follicle stimulating hormone (FSH) or human menopausalgonadotrophin (HMG) were randomly allocated doses of intra-nasal buserelinto induce an endogenous gonadotrophin surge, prior to oocyte collection.The doses ranged from a single 25 microg dose to 100 microg every 4 h for20 h. In three cycles the treatment was abandoned because of a poor ovarianresponse. In the remaining 31 cycles buserelin was given to induce theendogenous gonadotrophin surge, but there was evidence of prematureluteinization in eight cycles and a premature gonadotrophin surge in fourcycles. Although a single dose as low as 40 microg induced a surge andresulted in a pregnancy, a single dose of 50 microg proved the mosteffective minimal dose consistently to induce a gonadotrophin surge andoocyte maturation. Recent reports using gonadotrophin-releasing hormone(GnRH) analogues to induce a gonadotrophin surge has prompted publicationof this previously unpublished data.