Is in Vitro Maturation of Oocytes Influenced by the Origin of Gonadotropins Used in Maturation Medium: is There a Difference in Efficiency When Using Urinary Versus Recombinant Produced Follicle Stimulating Hormone and Human Chorionic Gonadotropin

Standard IVM currently contains urinary purified hormones which might contain contaminants possibly affecting maturation of embryo development. The investigators will test if the efficiency in terms of oocyte maturation after IVM of recombinant (without contaminants) is equivalent to urinary gonadotropins. Urinary and recombinant FSH and hCG will be used in equivalent bioactivity as measured in IU/ml and specified by the manufacturer. Sibling oocytes of the patient will be subjected to IVM medium containing urinary or recombinant gonadotropins. Oocyte maturation is the primary outcome, however, fertilization rate and preimplantation embryo development will be investigated.