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 III). Mice were killed at 116-120 hours (group I) and 44-48 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.