| ROBSON’S GROUP | Total delivery n = 7229 | Cesarean section n = 3100 | ||||
| A | Frequency | B | Relative contribution of each group to the overall rate of cesarean section | Rate of cesarean section in each group | ||
| Number | (A/Total delivery) × 100 | Number | (B/Total cesarean) × 100 | (B/A) × 100 | ||
| 1 | Nullipara, single pregnancy, cephalic presentation, gestational age ≥37 SA, spontaneous labor | 1887 | 26.1% | 637 | 20.5% | 33.7% |
| 2 | Nullipara, single pregnancy, cephalic presentation, gestational age ≥37 SA, onset of labor or cesarean section before labor | 318 | 4.4% | 277 | 8.9% | 87.1% |
| 3 | Multipara, single pregnancy, cephalic presentation, gestational age ≥37 SA, spontaneous labor, without cicatricial uterus | 2184 | 30.2% | 577 | 18.6% | 26.4% |
| 4 | Multipara, single pregnancy, cephalic presentation, gestational age ≥37 SA, onset of labor or caesarean before work, without cicatricial uterus | 347 | 4.8% | 270 | 8.7% | 77.8% |
| 5 | Previous cesarean section all multipara with at least a uterine scar, single pregnancy, cephalic presentation, gestational age ≥37 SA | 767 | 10.6% | 508 | 16.4% | 66.2% |
| 6 | All nullipara, single pregnancy, seat presentation | 145 | 2% | 95 | 3.1% | 65.5% |
| 7 | All multipara, single pregnancy seat presentation, cicatricial uterus included | 246 | 3.4% | 157 | 5.1% | 63.8% |
| 8 | All multiple pregnancies, cicatricial uterus included | 341 | 4.7% | 153 | 4.9% | 44.8% |
| 9 | All single pregnancies with transversal presentation, cicatricial uterus included | 47 | 0.6% | 47 | 1.5% | 100% |
| 10 | All single pregnancies with cephalic presentation, gestational age <37 SA, cicatricial uterus included | 947 | 13.1% | 379 | 12.2% | 40% |
| Total | 7229 | 100% | 3100 | 100% | 42.8% | |