Table 4. Maturation and fertilization status following IVM and IVF of oocytes vitrified in different combinations of penetrating CPA.
| Treatment groups | No. of oocytes |
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| Total* | GVBD | Matured$ | Penetrated | Normal | MPN | Monospermy | |
| (% total) | (% total) | (% GVBD) | (% GVBD) | (% penetrated) | (% penetrated) | ||
| Control | 100 | 98 (98.0 ± 1.1) | 77 (77.0 ± 3.0)a | 64 (65.1 ± 12.0) | 14 (14.2 ± 2.6) | 64 (100) | 19 (32.7 ± 9.2) |
| Vitrified-EG + PG | 100 | 98 (98.0 ± 1.1) | 69 (69.0 ± 6.6)ab | 57 (58.3 ± 6.2) | 20 (20.4 ± 6.0) | 54 (94.6 ± 3.1) | 29 (50.4 ± 3.5) |
| Vitrified-EG + DMSO | 100 | 99 (99.0 ± 1.0) | 81 (81.0 ± 3.7)a | 52 (52.5 ± 9.0) | 19 (19.1 ± 2.9) | 52 (100) | 23 (45.7 ± 3.1) |
| Vitrified-EG + PG + DMSO | 100 | 99 (99.0 ± 1.0) | 58 (58.0 ± 2.5)b | 47 (47.2 ± 12.7) | 8 (8.0 ± 1.5) | 45 (97.6 ± 2.3) | 16 (41.0 ± 8.9) |
Before vitrification, oocytes were equilibrated in a total of 4% (v/v) CPA of the actual CPA combination (treatment groups) for 15 min followed by a brief (approx. 40 sec) washing and vitrification in a total of 35% (v/v) CPA supplemented with sucrose (0.3 M). EG + PG = ethylene glycol + propylene glycol (1:1). EG + DMSO = ethylene glycol + dimethyl sulfoxide (1:1). EG + PG + DMSO = ethylene glycol + propylene glycol + dimethyl sulfoxide (1:1:1). Four replicates were performed. Percentage data are presented as mean ± SEM values. a, b Percentages with different letters in the same column differ significantly (P < 0.05). MPN = male pronucleus; GVBD = germinal vesicle breakdown. * After vitrification, IVM and IVF, only live oocytes used to assess nuclear and fertilization status. $At or beyond the MII stage at 10 h after IVF.