Influence of gonadotrophin-releasing hormone agonist total dose in the ovarian stimulation in the long down-regulation protocol for in-vitro fertilization

The goal of our study was to assess whether the total dose of gonadotrophin-releasing hormone agonist (GnRHa) administered affects the success of an in-vitro fertilization (IVF) programme. A retrospective analysis was performed on a total of 72 IVF cycles carried out on 70 patients with different causes of infertility included in our assisted reproduction programme. Cycles were divided into two groups according to the number of days of GnRHa administration (leuprolide acetate 1 mg/day) necessary until ovarian desensitization occurred: group I (GI) < 13 days (n = 27) and group II (GII) > or = 13 days (n = 45). The following parameters were assessed: number of gonadotrophin ampoules, number of stimulation days, endometrial thickness on the day of human chorionic gonadotrophin (HCG) administration, number of recovered oocytes, pregnancy rate. Pregnancy rate/cycle and pregnancy rate/transfer were positively correlated with the dose of GnRHa (GI: 44 and 60% respectively versus GII: 20% and 25% respectively). It is concluded that a long administration of GnRHa has no effect upon ovarian response, although the pregnancy rate is subsequently decreased.