Ovarian stimulation for in-vitro fertilization combining administration of gonadotrophins and blockade of the pituitary with D-Trp6-LHRH microcapsules: pilot studies with two protocols

Abstract

In women undergoing in-vitro fertilization and embryo transfer (IVF-ET), a total of 408 IVF cycles were stimulated using human menopausal gonadotrophin (HMG) or pure follicle stimulating hormone (FSH) plus HMG in combination with a single injection of D-Trp6-LHRH microcapsules in order to enhance the ovarian response to gonadotrophins and to avoid spontaneous LH surges. Sixty-seven pregnancies were achieved. Two protocols were employed. In protocol 1 ('blocking protocol', n = 268), the pituitary was first inhibited with a full dose (3.75 mg) of D-Trp6-LHRH in microcapsules and ovarian stimulation was started after the hypogonadotrophic hypogonadal state was ascertained (E2 less than 50 pg/ml). In protocol 2 ('flare-up protocol', n = 140), the treatment with D-Trp6-LHRH microcapsules (half-dose = 1.80 mg) and the ovarian stimulation with gonadotrophins were started at the same time. Higher doses of gonadotrophins were needed (39.5 +/- 11.2 ampoules FSH and/or HMG) in protocol 1, in which the pituitary was blocked prior to and during the stimulation, than in protocol 2 (20 +/- 9 ampoules) where the exogenous gonadotrophin stimulation appeared to be augmented by the initial agonistic effect of the injection of D-Trp6-LHRH microcapsules. In patients with purely tubal infertility, under 38 years old and no male factor, the results obtained with protocols 1 and 2 were similar in terms of pregnancy rate per cycle or per embryo transfer: 22.6 versus 20.5% and 28.3 versus 27.4%, respectively. However, considering the cost benefit, 'flare-up' protocols appeared to be a better choice and could be recommended.