Table 2.
Number of Potential Equine Zygotes with Abnormal Morphologies at 4, 6, 8, 12 and 16h After Intracytoplasmic Sperm Injection (0h) Per Total Injected Oocytes Matured In Vivo (IVO) or In Vitro (IVM).
| Abnormality | 4 h | 6 h | 8 h | 12 h | 16 h | Total Zygotes |
|---|---|---|---|---|---|---|
| Premature chromosome condensation | ||||||
| IVO | 0/5 (0) | 0/6 (0) | 0/5 (0) | 0/5 (0) | 0/7 (0) | 0/28 (0) |
| IVM | 1/8 (13) | 1/8 (13) | 2/8 (25) | 0/10 (0) | 1/10 (10) | 5/44 (11) |
| Multiple (>2) pronuclei | ||||||
| IVO | 0/5 (0) | 0/6 (0) | 0/5 (0) | 0/5 (0) | 0/7 (0) | 0/28 (0) |
| IVM | 1/8 (13) | 0/8 (0) | 0/8 (0) | 0/10 (0) | 0/10 (0) | 1/44 (3) |
| Sperm chromatin induced ectopic polar body | ||||||
| IVO | 0/5 (0) | 0/6 (0) | 0/5 (0) | 0/5 (0) | 0/7 (0) | 0/28 (0) |
| IVM | 0/8 (0) | 1/8 (13) | 3/8 (30) | 0/10 (0) | 0/10 (0) | 4/44 (9) |
| Multipolar spindle | ||||||
| IVO | 0/5 (0) | 0/6 (0) | 0/5 (0) | 1/5 (20) | 0/7 (0) | 1/28 (4) |
| IVM | 0/8 (0) | 0/8 (0) | 0/8 (0) | 0/10 (0) | 1/10 (10) | 1/44 (2) |
| Scattered chromosomes and sperm head intact | ||||||
| IVO | 0/5 (0) | 0/6 (0) | 0/5 (0) | 0/5 (0) | 2/7 (29) | 2/28 (7) |
| IVM | 0/8 (0) | 0/8 (0) | 0/8 (0) | 1/10 (10) | 1/10 (10) | 2/44 (5) |
| Total abnormalities | ||||||
| IVO | 0/5 (0) | 0/6 (0) | 0/5 (0) | 1/5 (20) | 2/7 (29) | 3/28a (11) |
| IVM | 2/8 (25) | 2/8 (25) | 5/8 (63) | 1/10 (10) | 3/10 (30) | 13/44b (30) |
The total number of zygotes with morphologic abnormalities was higher (p = 0.04) for IVM when compared to IVO (as denoted by bold numbers and different superscripts).