Insulin and IGF-1 does not alter the morphokinetics of mouse embryo development

Abstract

Objective To assess if there is a benefit to adding either IGF-1 or insulin to culture medium in terms of mouse embryo development using time-lapse morphokinetics. Design Prospective study. Materials and methods A total of 305 commercially obtained frozen mouse embryos (B6D2F1 & B6C3F1 hybrid) were thawed and cultured in (1) One-Step medium only, (2) One-Step medium with 100ng/mL insulin, and (3) One-Step medium with 100ng/mL IGF-1, using an EmbryoScope time lapse incubator at 37°C, 5.5% CO2, and 6.0% O2. The EmbryoScope was set to record images of each embryo every 10 minutes for 6 days of culture. The following time points were annotated: 2cell (t2), 3cell (t3), 4cell (t4), 5cell (t5), 6cell (t6), 7cell (t7), 8cell (t8), start of compaction (tSC), morula (tsM), start of blastulation (tSB), blastocyst (tB), expanded blastocyst (tEB) and hatching blastocyst (tHB). The 2-cell stage was considered as time zero since the exact time of insemination was unknown. All time points were statistically compared between each of the three groups. Blastocyst development rates for each group were also compared. Results A total of 304 blastocysts developed from the 316 embryos cultured, yielding an overall blastocyst development rate of 96.2%.When comparing the blastocyst development rate between the 3 groups, there were no significant differences between the One-Step and IGF-1 media groups (99.1% vs 96.2%). However, the insulin group showed significantly lower blastocyst rates when compared to the controls (93.3% vs 99.1%; p=0.02). There were no statistically significant differences in any of the time points measured between the One-Step, insulin and IGF-1 groups. Conclusions The data indicates that there is no beneficial effect of adding insulin or IGF-1 to culture media for mouse embryo development. Neither insulin not IGF-1 had any effect on the morphokinetics of these embryos. However, culture of mouse embryos in insulin supplemented media resulted in a lower blastocyst development rate compared to One-Step media. Ongoing studies are underway using a more sensitive mouse strain to see whether any changes in morphokinetics may be detected. Disclosures Nothing to disclose Funding None