The effect of pregnant mare serum gonadotropin on mouse embryos fertilized in vivo or in vitro.

The effect of increasing doses of exogenous gonadotropin stimulation for ovarian hyperstimulation was studied utilizing mouse embryos fertilized in vivo or in vitro. Increased rates of embryo degeneration, fragmentation, and triploidy, increased sister-chomatid exchange, and decreased fertilization rates were observed in high-dose stimulation groups. It appears, therefore, that oocyte and/or embryo quality may be affected by increased amounts of exogenous gonadotropin stimulation.