| Parameters | 1st group | 2nd group | 3rd group | 4th group |
| Number of examined fetuses | 24 | 24 | 24 | 24 |
| Skull | - | 2 (8.33%) | 3 (12.5%) | - |
| Sternbrea | - | 2 (8.33%) | 4 (16.66%) | - |
| Ribs | - | - | 1 (4.16%) | - |
| Digital bone | - | 1 (4.16%) | 3 (12.5%) | - |
| Caudal vertebrae | - | 2 (8.33%) | 3 (12.5%) | - |