['The development of preimplantation mammalian embryos in vitro is less than optimal. Follicular fluid and cumulus cells have both been used, independently, to improve preimplantation embryo quality in culture.', 'To determine the ability of mouse cumulus cell coculture in the presence of human follicular fluids to support preimplantation mouse Balb/cJ embryo development in vitro.', "Culture of preimplantation mouse Balb/cJ embryo's independently in human follicular fluid or on mouse cumulus cells had no significant affect on blastocyst. The coculture of mouse Balb/cJ preimplantation-stage embryos on mouse cumulus cells in the presence of human follicular fluid significantly (P < 0.01) improved blastocyst development and the total number of cells per blastocyst."] Do human follicular fluid and mouse cumulus cells act synergistically to enhance preimplantation mouse Balb/cJ embryo development?