| Variables |
| Frequency | % |
| Age | <18 years 18 - 35 years >35 years | 452 1476 26 | 23.1 75.5 1.3 |
| BMI (kg/m2) | <18.5 18.5 - 24.99 25 - 29.99 ≥30 | 40 1055 601 258 | 2.0 54.0 30.8 13.2 |
| PNC location | Monkole Referred | 1549 405 | 79.3 20.7 |
| Emergency degree | Extreme Absolute Relative | 192 445 317 | 9.8 22.8 67.4 |
| ASA Class | I II III IV | 317 535 66 3 | 67.4 27.4 3.0 0.2 |
| Cormack grade | I II | 122 21 | 6.0 1.0 |
| Glasgow at the admission | 15 9 - 14 <9 | 1924 27 3 | 98.5 1.4 0.2 |
| Hb level | ≤7 g/dl 7.1 - 10.9 g/dl ≥11 g/dl | 30 909 968 | 1.6 47.7 50.8 |
| Platelet count | <150,000 ≥150,000 | 308 1467 | 17.7 82.3 |
| Intraoperative transfusion | No Yes | 1831 123 | 93.7 6.3 |
| Type of anaesthesia | LRA GA | 1811 143 | 92.7 7.3 |
| Operative procedure | Caesarean section Hysterorrhaphy Caesarean/HST HST | 1917 26 7 4 | 98.1 1.3 0.3 0.2 |
| Operator | Senior Junior | 432 1522 | 22.1 79.9 |
| Anaesthesiologist | Senior Junior | 1350 604 | 69.1 30.9 |
| Time to intervention | Night Day | 858 1096 | 43.9 56.1 |