Table 6.
Distribution of the study population according to the Robson Classification and C-section rates per Robson Group, for the total population and by SEP
| Total | Housewives | Small business | Professional | Student | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Groupa | n in Robson Group | % of population in Robson Group % | C-section rate in Robson Group (%) | Contribution to CS rate of 16.5% (pp)b | n in Robson Group | % of housewives in Robson Group | C-section rate in Robson Group (%) | Contribution to CS rate of 15.8% (pp) | n in Robson Group | % of Small Business in Robson Group | C-section rate in Robson Group (%) | Contribution to CS rate of 18.4% (pp) | n in Robson Group | % of Professional in Robson Group | C-section rate in Robson Group (%) | Contribution to CS rate of 21.1% (pp) | n in Robson Group | % of students in Robson group | C-section rate in Robson Group (%) | Contribution to CS rate of 13.8% (pp) |
| 1&2 | 3757 | 31 | 13 | 4.1 | 1962 | 28 | 13 | 3.6 | 542 | 25 | 14 | 3.4 | 407 | 31 | 17 | 5.3 | 746 | 54 | 13 | 6.8 |
| 3&4 | 3308 | 27 | 7 | 1.9 | 2082 | 29 | 6 | 1.9 | 693 | 32 | 8 | 2.6 | 401 | 31 | 9 | 2.6 | 85 | 6 | 6 | 0.4 |
| 5 | 382 | 3 | 100 | 3.1 | 223 | 3 | 100 | 3.1 | 74 | 3 | 100 | 3.4 | 70 | 5 | 100 | 5.4 | 8 | 1 | 100 | 0.6 |
| 6 | 98 | 1 | 89 | 0.7 | 49 | 1 | 84 | 0.6 | 17 | 1 | 94 | 0.7 | 16 | 1 | 100 | 1.2 | 15 | 1 | 93 | 1.0 |
| 7 | 88 | 1 | 85 | 0.6 | 52 | 1 | 89 | 0.6 | 22 | 1 | 77 | 0.8 | 11 | 1 | 82 | 0.7 | 1 | 0 | 100 | 0.1 |
| 8 | 228 | 2 | 45 | 0.8 | 143 | 2 | 43 | 0.9 | 42 | 2 | 52 | 1.0 | 21 | 2 | 38 | 0.6 | 17 | 1 | 47 | 0.6 |
| 9 | 69 | 1 | 90 | 0.5 | 38 | 1 | 90 | 0.5 | 14 | 1 | 100 | 0.6 | 6 | 1 | 100 | 0.5 | 10 | 1 | 70 | 0.5 |
| 10 | 1163 | 10 | 15 | 1.4 | 714 | 10 | 14 | 1.4 | 203 | 9 | 17 | 1.6 | 84 | 6 | 14 | 0.9 | 144 | 11 | 13 | 1.4 |
| 11 | 1223 | 10 | 12 | 1.2 | 655 | 9 | 12 | 1.1 | 158 | 7 | 15 | 1.1 | 104 | 8 | 12 | 0.9 | 280 | 20 | 10 | 2.0 |
| 12 | 1622 | 13 | 14 | 1.9 | 1058 | 15 | 12 | 1.8 | 352 | 16 | 18 | 2.9 | 155 | 12 | 21 | 2.5 | 32 | 2 | 13 | 0.3 |
| missingc | 271 | 2 | 13 | 0.3 | 153 | 2 | 13 | 0.3 | 44 | 2 | 9 | 0.2 | 29 | 2 | 24 | 0.5 | 37 | 3 | 8 | 0.2 |
| Total | 12,209 | 100 | 17 | 16.5 | 7129 | 100 | 16 | 15.8 | 2161 | 100 | 18 | 18.4 | 1304 | 100 | 21 | 21.1 | 1375 | 100 | 14 | 13.8 |
aGroup:
1&2: Nullipara, singleton cephalic, 37+ weeks, spontaneous & induced labour
3&4: Multipara (excluding previous C-section) singleton cephalic, 37+ weeks, spontaneous & induced labour
5: Previous caesarean section, singleton cephalic, 37+ weeks
6: All nulliparous breeches
7: All multiparous breeches (including previous C-section)
8: All multiple pregnancies (including previous C-section)
9: All abnormal lies (including previous C-section but excluding breech)
10: All singleton cephalic, < 37 weeks (including previous C-section)
11: All nullipara, singleton cephalic, gestational age unknown (newly developed category)
12: All multipara, singleton cephalic, gestational age unknown (newly developed category)
bpp.: percentage point; c 271 women could not be divided in one of the Robson groups (also not in newly developed category 11 or 12), because of missing information on parity (16 records), number of fetuses (236 records) or a combination of missing parity and number of fetuses (19 records)