The effect of preimplantation culture conditions on murine embryo implantation and fetal development.

Ham's F-10 medium (Gibco, Grand Island, NY) and medium T6 with and without 15% fetal calf serum (FCS) were compared for their ability to support development of murine blastocysts with the capacity to implant and produce normal fetuses when transferred to pseudopregnant females. All media supported equal rates of blastocyst development from 2-cell embryos. In addition, there were no differences in the rates of blastocyst implantation. However, once implanted, blastocysts grown in T6 produced a significantly higher proportion of normal fetuses (58.5% to 65.9%) than blastocysts grown in either Ham's F-10 (2.4%) or T6 with FCS (27.6%). These results demonstrate that the rate of murine blastocyst development from 2-cell embryos in vitro is not a good criterion of healthy embryos. Murine blastocysts transferred in medium with 0% versus 50% FCS implanted and developed into normal fetuses at equal rates.