Endocrinology: Influence of serum follicle stimulating hormone to luteinizing hormone ratio during buserelin acetate-induced pituitary desensitizafion on ovarian response to exogenous gonadotrophins in an in-vitro fertilization and embryo transfer programme

We investigated the effect of endogenous gonadotrophins during pituitary 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 analysed 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 <30 pg/ml. The serum follicle stimulating hormone (FSH)/luteinizing hormone (LH) ratio, rather than serum FSH or LH concentrations during GnRHa-induced pituitary desensitization, showed a significant positive correlation with age and the total dose of exogenous gonadotrophins. The FSH/LH ratio also showed a significant negative correlation with oestradiol response and the number of retrieved oocytes, and was significantly lower in pregnant women compared with the non-pregnant group during pituitary desensitization. Our results indicate that, even under pituitary desensitization with GnRHa, the serum FSH/LH ratio influences individual ovarian responsiveness and the state of the intra-ovarian hormonal environment. Our results suggest that the FSH/LH ratio may be a useful clinical predictor of the ovarian response to exogenous gonadotrophins under pituitary desensitization.