The aim of this study was to evaluate the effect of methylprednisolone on t
he pregnancy rate in mice. For this reason, zona pellucida-intact and zona
pellucida-free embryos at the blastocyst stage were transferred to recipien
t mice at day 2.5 of pseudopregnancy. Embryo transfer was performed into no
n-immunodepressed and immunodepressed groups of recipient mice using 0.3 or
0.6 mu g/g of 6 beta-methylprednisolone. A higher implantation and develop
mental rate of zona-free embryos transferred to the immunodepressed group o
f recipients was observed after using the higher dose of methylprednisolone
.