INFLUENCE OF SERUM FOLLICLE-STIMULATING-HORMONE TO LUTEINIZING-HORMONE RATIO DURING BUSERELIN ACETATE-INDUCED PITUITARY DESENSITIZATION ON OVARIAN RESPONSE TO EXOGENOUS GONADOTROPINS IN AN IN-VITRO FERTILIZATION AND EMBRYO-TRANSFER PROGRAM

We investigated the effect of endogenous gonadotrophins during pituita ry desensitization with gonadotrophin-releasing hormone agonist (GnRHa ) on ovarian responsiveness or the outcome of in-vitro fertilization ( IVF) and embryo transfer, The results of 67 women who participated in the IVF programme at Nagasaki University Hospital, Japan, were analyse d retrospectively. All women received GnRHa from the third day of the menstrual cycle, and ovarian stimulation with exogenous gonadotrophins was initiated when the serum oestradiol concentration decreased to <3 0 pg/ml. The serum follicle stimulating hormone (FSH)/ luteinizing hor mone (LH) ratio, rather than serum FSH or LH concentrations during GnR Ha-induced pituitary desensitization, showed a significant positive co rrelation with age and the total dose of exogenous gonadotrophins. The FSH/LH ratio also showed a significant negative correlation with oest radiol response and the number of retrieved oocytes, and was significa ntly lower in pregnant women compared with the non-pregnant group duri ng pituitary desensitization. Our results indicate that, even under pi tuitary desensitization with GnRHa, the serum FSH/LH ratio influences individual ovarian responsiveness and the state of the intra-ovarian h ormonal environment. Our results suggest that the FSH/LH ratio may be a useful clinical predictor of the ovarian response to exogenous gonad otrophins under pituitary desensitization.