Recombinant human leukemia inhibitory factor enhances the development of preimplantation mouse embryo in vitro

Objective: To assess the effect of recombinant human leukemia inhibitory factor (rhLIF) on mouse embryos in vitro. Design: Controlled prospective study. Setting: Academic research environment. Animal(s): Female CB6F1 mice between 6 and 8 weeks old, Intervention(s): Mice were divided randomly into three groups, which included a control group in an in vivo study (group I) and two groups in an in vitro study (groups II and mi. Mice were killed at 116-120 hours (group I) and 34-48 hours (groups II and III) after hCG injection. Two-cell embryos (groups II and III) and blastocysts (group I) were obtained. Embryos in group II were cocultured with human tubal fluid (HTF) + 0.5% human serum albumin and in group III with HTF + rhLIF (1,000 U/mL) under paraffin oil. Main Outcome Measure(s): The embryonic numbers in different stages were recorded and compared. Result(s): Similar early embryo development to the four- to eight-cell and morula stages was noted between groups II and III (87.3% versus 91.0% and 74.6% versus 87.1%, respectively). However, further embryo development to the blastocyst, expanded blastocyst, and hatching blastocyst in group II(48.1%, 31.7%, and 18.5%. respectively) was lower than that in group III (83.6%, 53.7% and 37.8%). Conclusion(s): RhLIF does not provide obvious stimulation in the early mouse embryo. However, rhLIF has positive effects on preimplantation blastocyst growth, differentiation, and hatching. (C) 1999 by American Society for Reproductive Medicine.