Table 2.
Effects of different oxygen concentrations on the development of preimplantation embryos and cell number of blastocysts.
| On day 5 after hCG injection | HO (20%) | LO (5%) | DO (5% to 2% O2) |
|---|---|---|---|
| Percentage of blastocysts | 70.5%a (124/176) | 73.9%a (136/184) | 72.7%a (149/205) |
| Percentage of hatching blastocysts | 32.3%a (40/124) | 39.7%a (54/136) | 49.7%b (74/149) |
| Number of cells in ICM† | 14.6 ± 0.7a (n = 28) | 17.4 ± 1.2ab (n = 33) | 19.5 ± 1.1b (n = 30) |
| Number of cells in TE† | 47.8 ± 2.5a (n = 28) | 58.0 ± 3.8ab (n = 33) | 64.1 ± 3.4b (n = 30) |
| Total cell number† | 62.4 ± 2.4a (n = 28) | 75.4 ± 4.2a (n = 33) | 83.6 ± 3.8b (n = 30) |
| ICM/total cell number ratio† | 24.2 ± 1.43a (n = 28) | 24.0 ± 1.3a (n = 33) | 24.1 ± 1.3a (n = 30) |
A total of 49 female mice were corresponded to the blastocysts. Percentages for blastocyst formation and hatching were analyzed by SPSS statistics. †Values are represented as mean ± SEM for each group and analyzed by one-way ANOVA using Tukey's multiple comparison test. HO: high oxygen (20%); LO: low oxygen (5%); DO: dynamic oxygen (5% to 2%); ICM: inner cell mass; TE: trophectoderm. a,bDifferent superscript letters indicate statistically significant differences (p < 0.05).