Table 1. Characteristics of cases and controls.
| Controls N = 762 n(%) | PPH N = 3852 n(%) | p | Severe PPH N = 1048 n(%) | p | |
|---|---|---|---|---|---|
| Maternal age (years) | |||||
| ≤25 | 187 (24.5) | 943 (24.5) | 243 (23.2) | ||
| 26–35 | 521 (68.4) | 2536 (65.9) | 709 (67.7) | ||
| >35 | 54 (7.1) | 369 (9.6) | 0.09 | 96 (9.2) | 0.26 |
| BMI (kg/m 2 ) | |||||
| ≤25 | 545 (71.5) | 2791 (72.5) | 758 (72.3) | ||
| 26–30 | 79 (10.4) | 467 (12.1) | 121 (11.5) | ||
| >30 | 28 (3.7) | 193 (5.0) | 53 (5.1) | ||
| Missing value | 110 (14.4) | 401 (10.4) | 0.22 | 116 (11.1) | 0.38 |
| Gestational age (weeks) | |||||
| <37 | 32 (4.2) | 117 (3.1) | 33 (3.1) | ||
| 37–40 | 594 (78.0) | 2778 (74.5) | 745 (71.1) | ||
| ≥41 | 136 (17.8) | 953 (25.5) | <0.01 | 270 (25.7) | <0.01 |
| Induction of labor | 136 (17.9) | 933(24.2) | <0.01 | 255 (24.3) | <0.01 |
| Total oxytocin dose during labor (IU) | |||||
| 0 | 213 (29.7) | 797 (21.0) | 203 (19.7) | ||
| ]0–0.57] | 147 (20.5) | 636 (16.8) | 174 (16.9) | ||
| ]0.57–1.68] | 179 (25.0) | 926 (24.5) | 227 (22.0) | ||
| >1.68 | 178 (24.8) | 1428 (37.7) | <0.01 | 428 (41.5) | <0.01 |
| Epidural | 647 (84.9) | 3412 (88.6) | <0.01 | 920 (87.8) | 0.08 |
| Duration of previous phases of labor (h) (mean +/- SD) | 5.3 ±2.8 | 6.1 ±3.1 | <0.01 | 6.2 ±3.1 | <0.01 |
| Mode of delivery | |||||
| Spontaneous | 565 (74.1) | 2415 (62.7) | 595 (56.8) | ||
| Forceps | 130 (17.1) | 1124 (29.2) | 373 (35.6) | ||
| Vacuum | 67 (8.8) | 313 (8.1) | <0.01 | 80 (7.6) | <0.01 |
| Episiotomy | 433 (56.8) | 2638 (68.5) | <0.01 | 773 (73.8) | <0.01 |
| Perineal tear | 209 (27.5) | 1124 (29.2) | 0.34 | 313 (29.9) | 0.27 |
| Prophylactic postpartum oxytocin administration | 560 (73.5) | 2270 (58.9) | <0.01 | 612 (58.4) | <0.01 |
| Birth weight (g) | |||||
| ≤3000 | 231 (30.3) | 697 (18.1) | 177 (16.9) | ||
| 3001–3500 | 332 (43.6) | 1630 (42.3) | 422 (40.3) | ||
| 3501–4000 | 176 (23.1) | 1228 (31.9) | 353 (33.7) | ||
| >4000 | 22 (2.9) | 293 (7.6) | <0.01 | 95 (9.1) | <0.01 |
| Annual number of deliveries in unit | |||||
| ≤1500 | 273 (35.8) | 1284 (33.3) | 345 (32.9) | ||
| 1501–3000 | 404 (53.0) | 1980 (51.4) | 524 (50.0) | ||
| >3000 | 85 (11.2) | 588 (15.3) | <0.01 | 179 (17.1) | <0.01 |
| Status of the maternity unit | |||||
| Public university | 162 (21.3) | 1168 (30.3) | 317 (30.2) | ||
| Public non-university | 374 (49.1) | 1973 (51.2) | 539 (51.4) | ||
| Private | 226 (29.7) | 711 (18.5) | <0.01 | 192 (18.3) | <0.01 |
| Level of the maternity unit | |||||
| Level 1 | 255 (33.5) | 1095 (28.4) | 293 (28.0) | ||
| Level 2 | 390 (51.2) | 1898 (49.3) | 508 (48.5) | ||
| Level 3 | 117 (15.4) | 859 (22.3) | <0.01 | 247 (23.6) | <0.01 |
| Group of randomization in PITHAGORE6 trial | 396 (52.0) | 1782 (46.3) | <0.01 | 529 (50.5) | 0.53 |