| Maternal outcome | No previous vaginal deliveries | ≥ 1 Previous vaginal deliveries | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Planned vaginal, no. (%) n = 7 614 | Planned CS, no. (%) n = 20 792 | RR (95% CI) | Planned vaginal, no. (%) n = 3 726 | Planned CS, no. (%) n = 1 680 | RR (95% CI) | |||||||
| Life-threatening or death | ||||||||||||
| Maternal death | 0 | 0 | – | 0 | 0 | – | ||||||
| Uterine rupture | 33 | (0.4) | 13 | (0.06) | 6.93 | (3.65–13.16) | 7 | (0.2) | 1 | (0.06) | 3.16 | (0.39–25.63) |
| Hemorrhage requiring blood transfusion | 46 | (0.6) | 87 | (0.4) | 1.44 | (1.01–2.06) | 19 | (0.5) | 12 | (0.7) | 0.71 | (0.35–1.47) |
| Surgical control of bleeding* | 89 | (1.2) | 45 | (0.2) | 5.40 | (3.78–7.72) | 51 | (1.4) | 3 | (0.2) | 7.67 | (2.40–24.52) |
| Hysterectomy | 2 | (0.03) | 23 | (0.1) | 0.24 | (0.06–1.01) | 1 | (0.03) | 1 | (0.06) | 0.45 | (0.03–7.20) |
| Complications of anesthesia† | 3 | (0.04) | 11 | (0.05) | 0.74 | (0.21–2.67) | 1 | (0.03) | 0 | – | ||
| Deep vein thrombosis | 0 | 5 | (0.02) | – | 0 | 0 | – | |||||
| Pulmonary embolism | 0 | 3 | (0.01) | – | 0 | 0 | – | |||||
| Obstetric septic embolism | 0 | 1 | – | 0 | 0 | – | ||||||
| Amniotic embolism | 0 | 1 | – | 0 | 0 | – | ||||||
| ≥ 1 Life-threatening outcome | 165 | (2.2) | 179 | (0.9) | 2.52 | (2.04–3.11) | 73 | (2.0) | 16 | (0.9) | 2.06 | (1.20–3.52) |
| Non–life threatening | ||||||||||||
| Uterine dehiscence | 62 | (0.8) | 58 | (0.3) | 2.94 | (2.04–4.17) | 18 | (0.5) | 7 | (0.4) | 1.16 | (0.49–2.77) |
| Complications of anesthesia‡ | 43 | (0.6) | 115 | (0.5) | 1.02 | (0.72–1.45) | 9 | (0.2) | 1 | (0.06) | 4.06 | (0.51–32.00) |
| Obstetric surgical wound infection | 50 | (0.7) | 252 | (1.2) | 0.54 | (0.40–(0.73) | 17 | (0.5) | 29 | (1.7) | 0.26 | (0.15–0.48) |
| Puerperal infection | 19 | (0.3) | 133 | (0.6) | 0.39 | (0.24–(0.63) | 8 | (0.2) | 15 | (0.9) | 0.24 | (0.10–0.57) |
| Puerperal sepsis | 9 | (0.1) | 23 | (0.1) | 1.07 | (0.49–2.31) | 1 | (0.03) | 3 | (0.2) | 0.15 | (0.02–1.44) |
| ≥ 1 Non–life threatening outcome | 159 | (2.1) | 439 | (2.1) | 0.99 | (0.82–1.18) | 45 | (1.2) | 40 | (2.4) | 0.51 | (0.33–0.77) |
Note: CI = confidence interval, RR = relative risk. *Surgical control of bleeding uterus and surrounding structures, or dilation and curettage following delivery. †Pulmonary, cardiac or central nervous system complications of anesthesia, including aspiration pneumonitis, toxic reaction to anesthesia and failed or difficult intubation. ‡Spinal and epidural induced headache, other and unspecified complications of anesthesia.