Background
Methods
Source of data and subjects
Robson groups and covariables
Total | Public | Private | Chi square P-value* | ||||
---|---|---|---|---|---|---|---|
n
| % |
n
| % |
n
| % | ||
Total | 23,894 | 19,129 | 4,765 | - | |||
Maternal age | |||||||
< 20 | 4,571 | 19.1 | 4,325 | 22.6 | 246 | 5.2 | <0.001 |
20–34 | 16,807 | 70.4 | 13,162 | 68.8 | 3,645 | 76.5 | |
> 34 | 2,509 | 10.5 | 1,635 | 8.6 | 874 | 18.3 | |
Skin color | |||||||
White | 8,078 | 33.8 | 5,484 | 28.7 | 2,594 | 54.4 | <0.001 |
Black | 2,051 | 8.6 | 1,892 | 9.9 | 159 | 3.3 | |
Pardo/Mixed | 13,404 | 56.1 | 11,457 | 59.9 | 1,947 | 40.9 | |
Yellow | 257 | 1.1 | 202 | 1.1 | 55 | 1.2 | |
Indigenous | 99 | 0.4 | 89 | 0.5 | 10,0 | 0.2 | |
Marital status | |||||||
Live with a partner | 19,440 | 81.4 | 15,177 | 79.4 | 4,263 | 89.5 | <0.001 |
Do not live with a partner | 4,431 | 18.6 | 3,931 | 20.6 | 500 | 10.5 | |
Years of schooling | |||||||
≤ 7 | 6,363 | 26.5 | 6,197 | 32.4 | 166 | 3.5 | <0.001 |
8 to 10 | 6,104 | 25.6 | 5,604 | 29.3 | 500 | 10.5 | |
11 to 14 | 9,310 | 39.0 | 6,790 | 35.5 | 2,520 | 52.9 | |
≥ 15 | 2,112 | 8.9 | 535 | 2.8 | 1,577 | 33.1 | |
Parity | |||||||
0 | 11,208 | 46.9 | 8,569 | 44.8 | 2,639 | 55.4 | <0.001 |
1 | 7,015 | 29.4 | 5,405 | 28.3 | 1,610 | 33.8 | |
≥ 2 | 5,671 | 23.7 | 5,155 | 26.9 | 516 | 10.8 | |
Previous cesarean** | |||||||
0 | 7,571 | 59.7 | 6,885 | 65.2 | 686 | 32.2 | <0.001 |
1 | 3,905 | 30.8 | 2,689 | 25.5 | 1,216 | 57.2 | |
≥ 2 | 1,211 | 9.5 | 986 | 9.3 | 225 | 10.6 | |
Type of pregnancy | |||||||
Single | 23,610 | 98.8 | 18,936 | 99.0 | 4,674 | 98.1 | <0.001 |
Multiple | 284 | 1.2 | 192 | 1.0 | 92 | 1.9 | |
Induction of labor | |||||||
yes | 2,729 | 11.4 | 2,561 | 13.4 | 168 | 3.5 | <0.001 |
no | 21,165 | 88.6 | 16,568 | 86.6 | 4,597 | 96.5 | |
Labor (spontaneous or induced) | |||||||
yes | 13,458 | 56.3 | 12,618 | 66.0 | 840 | 17.6 | <0.001 |
no | 10,436 | 43.7 | 6,511 | 34.0 | 3,925 | 82.4 | |
Delivery | |||||||
Vaginal | 11,152 | 46.7 | 10,605 | 55.4 | 547 | 11.5 | <0.001 |
Forceps/Vaccum | 347 | 1.5 | 317 | 1.7 | 30 | 0.6 | |
Cesarean | 12,395 | 51.9 | 8,207 | 42.9 | 4,188 | 87.9 | |
High obstetric risk*** | |||||||
yes | 5,677 | 23.8 | 4,487 | 23.5 | 1,190 | 25.0 | 0.225 |
no | 18,217 | 76.2 | 14,642 | 76.5 | 3,575 | 75.0 |
Statistical analysis
Results
Robson group | Description of obstetric populations | Number of cesarean deliveries | Number of deliveries | Relative (%) size of group1
| CS rate (%) in each group | Absolute contribution (%) on the overall CS rate2
| Relative (%) contribution on the overall CS rate3
|
---|---|---|---|---|---|---|---|
1 | Nulliparous women, single cephalic, > = 37 weeks, in spontaneous labor | 848 | 4,330 | 18.1 | 19.6 | 3.5 | 6.8 |
2 | Nulliparous women, single cephalic, > = 37 weeks, induced or CS before labor | 4,169 | 4,988 | 20.9 | 83.6 | 17.4 | 33.6 |
2a | Nulliparous women, single cephalic, > = 37 weeks, induced labor | 618 | 1,437 | 6.0 | 43.0 | 2.6 | 5.0 |
2b | Nulliparous women, single cephalic, > = 37 weeks, CS before labor | 3,551 | 3,551 | 14.9 | 100.0 | 14.9 | 28.6 |
3 | Multiparous women (excluding prev. CS), single cephalic, > = 37 weeks, in spontaneous labor | 264 | 4,775 | 20.0 | 5.5 | 1.1 | 2.1 |
4 | Multiparous women without a previous uterine scar, with single cephalic pregnancy, > = 37 weeks, induced or CS before labor | 1,028 | 1,685 | 7.1 | 61.0 | 4.3 | 8.3 |
4a | Multiparous women without a previous uterine scar, with single cephalic pregnancy, > = 37 weeks, induced labor | 127 | 784 | 3.3 | 16.2 | 0.5 | 1.0 |
4b | Multiparous women without a previous uterine scar, with single cephalic pregnancy, > = 37 weeks, CS before labor | 901 | 901 | 3.8 | 100.0 | 3.8 | 7.3 |
5 | Previous CS, single cephalic, > = 37 weeks | 3,816 | 4,562 | 19.1 | 83.6 | 16.0 | 30.8 |
6 | All nullipara breeches | 409 | 425 | 1.8 | 96.2 | 1.7 | 3.3 |
7 | All multipara breeches (including prev. CS) | 338 | 399 | 1.7 | 84.7 | 1.4 | 2.7 |
8 | All multiple pregnancies (including prev. CS) | 240 | 283 | 1.2 | 84.8 | 1.0 | 1.9 |
9 | All abnormal lies (including prev. CS) | 114 | 114 | 0.5 | 100.0 | 0.5 | 0.9 |
10 | All single cephalic, <=36 weeks (including prev. CS) | 1,166 | 2,326 | 9.7 | 50.1 | 4.9 | 9.4 |
X | Unable to classify | 3 | 7 | 0.0 | 42.9 | 0,0 | 0.0 |
Total | 12,395 | 23,894 | 100 | 51.9 | 51.9 | 100 |
Robson group | Description of obstetric populations | Number of cesarean deliveries | Number of deliveries | Relative size of group1,a
| CS rate in each group2,b
| Relative contribution on the overall CS rate3,c
| |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Public | Private | Public | Private | Public | Private | Public | Private | Public | Private | ||||||||
% | 95 % CI | % | 95 % CI | % | 95 % CI | % | 95 % CI | % | 95 % CI | % | 95 % CI | ||||||
1 | Nulliparous women, single cephalic, > = 37 weeks, in spontaneous labor | 712 | 136 | 4,023 | 307 | 21.0 | (19.5–22.2) | 6.4 | (5.1–7.7) | 17.7 | (15.1–20.6) | 44.4 | (35.5–53.5) | 8.7 | (7.5–10.1) | 3.2 | (2.6–4.1) |
2 | Nulliparous women, single cephalic, > = 37 weeks, induced or CS before labour | 2,351 | 1,818 | 3,116 | 1,872 | 16.3 | (15.2–17.1) | 39.3 | (36.2–40.7) | 75.4 | (71.2–79.2) | 97.1 | (93.3–98.8) | 28.6 | (26.9–30.4) | 43.4 | (41.2–45.7) |
2ª | Nulliparous women, single cephalic, > = 37 weeks, induced labor | 566 | 52 | 1,331 | 106 | 7.0 | (6.1–8.0) | 2.2 | (1.3–3.7) | 42.5 | (36.8–48.4) | 49.1 | (29.6–69.1) | 6.9 | (5.7–8.3) | 1.2 | (0.8–1.9) |
2b | Nulliparous women, single cephalic, > = 37 weeks, CS before labor | 1,785 | 1,766 | 1,785 | 1,766 | 9.3 | (8.5–10.3) | 37.1 | (34.5–39.7) | 100.0 | - | 100.0 | - | 21.8 | (20.3–23.3) | 42.2 | (39.9–44.4) |
3 | Multiparous women (excluding prev. CS), single cephalic, > = 37 weeks, in spontaneous labor | 234 | 30 | 4,520 | 255 | 23.6 | (22.3–24.6) | 5.4 | (4.0–6.9) | 5.2 | (4.1–6.5) | 11.8 | (7.2–18.1) | 2.9 | (2.3–3.5) | 0.7 | (0.5–1.0) |
4 | Multiparous without a previous uterine scar, with single cephalic pregnancy, > = 37 weeks, induced or CS before labor | 758 | 270 | 1,379 | 306 | 7.2 | (6.5–7.8) | 6.4 | (5.3–7.4) | 55.0 | (50.0–59.8) | 88.2 | (80.1–93.2) | 9.2 | (8.4–10.1) | 6.4 | (5.4–7.6) |
4ª | Multiparous women without a previous uterine scar, with single cephalic pregnancy, > = 37 weeks, induced labor | 118 | 9 | 739 | 45 | 3.9 | (3.3–4.5) | 0.9 | (0.6–1.6) | 16.0 | (13.0–19.6) | 19.5 | (8.7–38.1) | 1.4 | (1.1–1.8) | 0.2 | (0.1–0.5) |
4b | Multiparous women without a previous uterine scar, with single cephalic pregnancy, > = 37 weeks, CS before labor | 640 | 261 | 640 | 261 | 3.3 | (3.0–3.8) | 5.5 | (4.5–6.6) | 100.0 | - | 100.0 | - | 7.8 | (7.0–8.6) | 6.2 | (5.2–7.4) |
5 | Previous CS, single cephalic, > = 37 weeks | 2,556 | 1,260 | 3,276 | 1,286 | 17.1 | (16.0–18.0) | 27.0 | (24.8–28.1) | 78.0 | (75.4–80.4) | 98.0 | (96.5–98.9) | 31.1 | (29.7–32.7) | 30.1 | (28.5–31.8) |
6 | All nullipara breeches | 271 | 138 | 286 | 139 | 1.5 | (1.3–1.7) | 2.9 | (2.0–4.0) | 94.4 | (91.2–96.9) | 99.3 | (96.5–99.9) | 3.3 | (2.8–3.8) | 3.3 | (2.3–4.6) |
7 | All multipara breeches (including prev. CS) | 276 | 62 | 336 | 63 | 1.8 | (1.5–2.1) | 1.3 | (1.0–1.7) | 82.1 | (71.9–89.1) | 98.4 | (93.0–99.6) | 3.4 | (2.9–3.9) | 1.5 | (1.2–1.9) |
8 | All multiple pregnancies (including prev. CS) | 153 | 87 | 191 | 92 | 1.0 | (0.8–1.2) | 1.9 | (1.5–2.6) | 79.7 | (72.1–85.6) | 94.6 | (72.7–99.1) | 1.9 | (1.5–2.3) | 2.1 | (1.5–3.0) |
9 | All abnormal lies (including prev. CS) | 91 | 23 | 91 | 23 | 0.5 | (0.4–0.6) | 0.5 | (0.3–0.8) | 100.0 | - | 100.0 | - | 1.1 | (0.9–1.4) | 0.5 | (0.3–0.9) |
10 | All single cephalic, <=36 weeks (including prev. CS) | 803 | 363 | 1,904 | 422 | 10.0 | (8.7–11.2) | 8.9 | (7.1–10.6) | 42.2 | (38.7–45.7) | 86.0 | (78.3–91.1) | 9.8 | (8.3–11.5) | 8.7 | (6.9–10.9) |
X | Unable to classify | 2 | 1 | 6 | 1 | 0.03 | (0.01–0.07) | 0.02 | (0.002–0.01) | 40.2 | (7.8–84.2) | 100.0 | - | 0.0 | - | 0.0 | - |
Total deliveries | 8,207 | 4,188 | 19,128 | 4,766 | 100.0 | - | 100.0 | - | 41.5 | - | 87.9 | - | 100.0 | 100.0 |
Robson group | Public | Private | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Low risk women1
| High risk women2
| Low risk women1
| High risk women2
| |||||||||||||
All | CS | % | 95 % CIa
| All | CS | % | 95 % CIa
| All | CS | % | 95 % CIb
| All | CS | % | 95 % CIb
| |
All groups | 14,640 | 5,168 | 35.3 | (33.0–37.6) | 4,484 | 3,036 | 67.7 | (64.9–70.4) | 3,573 | 3,082 | 86.3 | (81.2–90.1) | 1,190 | 1,104 | 92.8 | (89.5–95.0) |
1 | 3,475 | 477 | 13.7 | (11.2–16.6) | 550 | 236 | 42.9 | (36.8–49.2) | 253 | 110 | 43.4 | (33.8–53.4) | 54 | 26 | 48.7 | (29.9–67.8) |
2 | 2,114 | 1,465 | 69.3 | (63.9–74.2) | 1,002 | 885 | 88.4 | (85.2–91.0) | 1,425 | 1,376 | 96.6 | (91.4–98.7) | 444 | 441 | 99.0 | (96.9–99.7) |
3 | 3,886 | 137 | 3.5 | (2.6–4.7) | 636 | 97 | 15.3 | (11.2–20.4) | 214 | 23 | 10.7 | (6.5–17.2) | 41 | 7 | 16.1 | (7.6–30.9) |
4 | 911 | 434 | 47.6 | (42.1–53.2) | 467 | 324 | 69.3 | (62.9–75.1) | 220 | 192 | 87.3 | (77.7–93.1) | 85 | 77 | 90.4 | (82.2–95.0) |
5 | 2,410 | 1,799 | 74.7 | (71.3–77.8) | 866 | 756 | 87.3 | (84.3–89.7) | 1,002 | 978 | 97.6 | (95.7–98.7) | 284 | 283 | 99.6 | (97.5–100.0) |
8 | 125 | 95 | 75.7 | (66.4–83.1) | 67 | 59 | 88.6 | (79.6–93.9) | 67 | 62 | 92.3 | (63.0–98.8) | 25 | 25 | 100.0 | - |
10 | 1,208 | 306 | 25.4 | (21.8–29.2) | 694 | 497 | 71.4 | (65.4–76.8) | 222 | 172 | 77.6 | (67.5–85.3) | 201 | 190 | 94.9 | (88.3–97.9) |
6, 7 and 9 | 511 | 455 | 89.1 | (81.4–93.9) | 202 | 182 | 90.3 | (83.0–94.6) | 170 | 169 | 99.4 | (97.4–99.9) | 56 | 55 | 98.7 | (91.4–99.8) |