The Effect of Prolactin on the Early Embryogenesis of Mice in Vitro

It is said the prolactin (PRL) is correlated with fetal lung maturation during late pregnancy. However, there are few reports about PRL during early pregnancy and the period of peri-implantation. Recently, transient hyperprolactinemia at the preovulatory phase or after follicle aspiration for in vitro fertilization has been reported. Nonetheless, the effect of high PRL on the folliculogenesis and the early embryogenesis is still controversial. Moreover, some researchers reported that human fetal umbilical cord sera was good for the development of ova fertilized in vitro. Therefore, we studied the effect of graded concentrations of PRL (10, 30, 100 ng/ml) on the development of embryos fertilized in vivo or in vitro using ddY mice. We concluded that higher PRL levels caused a smaller number of developed embryos, in statistical significance, into blastocysts and hatched blastocysts. In general, embryos fertilized in vivo developed better than those fertilized in vitro.