The use of gonadotrophin-releasing hormone analogues in women receiving oocyte donation does not affect implantation rates.

There is conflicting clinical evidence suggesting a positive role for gonadotrophin-releasing hormone analogues (GnRHa) on implantation in humans. This potential effect was evaluated in this study taking the oocyte donation programme as a model. Patients were randomly allocated into one of the two treatment groups: group I received simultaneous treatment with GnRHa and steroids, and group II only received exogenous steroid replacement. An analysis of the donors and semen quality showed similarity between recipient groups. There was no significant difference between groups in the number and quality of embryos replaced, clinical pregnancy and implantation rates. In summary, using a model in which the endometrium can be analysed independently of the embryos, the results suggest that GnRHa are neither effective nor detrimental for embryo implantation in humans.