DEVELOPMENT OF HATCHING BLASTOCYSTS FROM IMMATURE HUMAN OOCYTES FOLLOWING IN-VITRO MATURATION AND FERTILIZATION USING A COCULTURE SYSTEM

Recently, in-vitro maturation (IVM) of immature human oocytes recovere d from non-stimulated follicles has been applied in the treatment of i nfertility. However, in previous reports, very few embryos cultured in conventional medium have reached the expanded blastocyst stage follow ing in-vitro maturation and fertilization (IVM/IVF). The objective of this study was to investigate whether the developmental competence of human embryos following IVM/IVF could be enhanced by the use of a huma n ampullary cell coculture system. Immature human oocytes were aspirat ed from small follicles at Caesarean section and then cultured in medi um containing human menopausal gonadotrophin for 36 to 48 h, followed by insemination, Zygotes were randomly cultured either in conventional culture medium alone or in the co-culture system, Of 48 embryos cultu red in conventional medium alone, all arrested at the 2-16-cell stage on day 3 after insemination, Of 46 embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at the 2-16-cell stage, Six embryo s (13%) developed to the morula stage. Fourteen embryos (30.4%) develo ped to expanded blastocysts and two blastocysts were hatching on day 7 after insemination, We conclude that co-culture significantly enhance s the development of blastocysts in embryos resulting from IVM/IVF.