Outcome | No. of deliveries | Rate per 1000 deliveries | Crude RR (95% CI) | Adjusted RR† (95% CI) |
---|---|---|---|---|
Uterine rupture | ||||
Elective repeat cesarean | 243 | 1.75 | 1.00 (Ref.) | 1.00 (Ref.) |
Attempted VBAC | 583 | 9.93 | 5.72 (4.92 to 6.65) | 5.24 (4.48 to 6.12) |
Successful VBAC | 38 | 1.30 | 0.74 (0.53 to 1.04) | 0.64 (0.45 to 0.90) |
Failed VBAC | 545 | 18.5 | 10.8 (9.24 to 12.5) | 9.62 (8.23 to 11.3) |
Rupture not including dehiscence | ||||
Elective repeat cesarean | 69 | 0.50 | 1.00 (Ref.) | 1.00 (Ref.) |
Attempted VBAC | 194 | 3.30 | 6.67 (5.07 to 8.78) | 6.41 (4.84 to 8.50) |
Successful VBAC | 15 | 0.51 | 1.03 (0.59 to 1.80) | 0.94 (0.54 to 1.66) |
Failed VBAC | 179 | 6.08 | 12.3 (9.32 to 16.2) | 11.6 (8.77 to 15.5) |
PPH and blood transfusion | ||||
Elective repeat cesarean | 226 | 1.63 | 1.00 (Ref.) | 1.00 (Ref.) |
Attempted VBAC | 264 | 4.50 | 2.77 (2.32 to 3.31) | 2.80 (2.33 to 3.37) |
Successful VBAC | 153 | 5.23 | 3.22 (2.63 to 3.96) | 3.34 (2.69 to 4.14) |
Failed VBAC | 111 | 3.77 | 2.32 (1.85 to 2.91) | 2.32 (1.84 to 2.92) |
PPH and procedures for bleeding | ||||
Elective repeat cesarean | 213 | 1.53 | 1.00 (Ref.) | 1.00 (Ref.) |
Attempted VBAC | 125 | 2.13 | 1.39 (1.11 to 1.73) | 1.44 (1.15 to 1.82) |
Successful VBAC | 19 | 0.65 | 0.42 (0.26 to 0.68) | 0.44 (0.28 to 0.72) |
Failed VBAC | 106 | 3.60 | 2.35 (1.86 to 2.97) | 2.33 (1.83 to 2.97) |
PPH and hysterectomy | ||||
Elective repeat cesarean | 76 | 0.55 | 1.00 (Ref.) | 1.00 (Ref.) |
Attempted VBAC | 32 | 0.55 | 1.00 (0.66 to 1.51) | 1.05 (0.68 to 1.62) |
Successful VBAC | 5 | 0.17 | 0.31 (0.13 to 0.77) | 0.33 (0.13 to 0.84) |
Failed VBAC | 27 | 0.92 | 1.68 (1.08 to 2.60) | 1.67 (1.06 to 2.64) |
Maternal morbidity and mortality‡ | ||||
Elective repeat cesarean | 784 | 5.65 | 1.00 (Ref.) | 1.00 (Ref.) |
Attempted VBAC | 629 | 10.7 | 1.91 (1.72 to 2.12) | 1.96 (1.76 to 2.19) |
Successful VBAC | 209 | 7.14 | 1.27 (1.09 to 1.48) | 1.32 (1.13 to 1.55) |
Failed VBAC | 420 | 14.3 | 2.55 (2.26 to 2.87) | 2.54 (2.25 to 2.87) |
Restricted severe morbidity¶ | ||||
Elective repeat cesarean | 645 | 4.65 | 1.00 (Ref.) | 1.00 (Ref.) |
Attempted VBAC | 422 | 7.19 | 1.55 (1.37 to 1.76) | 1.63 (1.43 to 1.85) |
Successful VBAC | 73 | 2.49 | 0.54 (0.42 to 0.68) | 0.57 (0.45 to 0.73) |
Failed VBAC | 349 | 11.9 | 2.57 (2.26 to 2.93) | 2.58 (2.25 to 2.95) |
Note: CI = confidence interval, PPH = postpartum hemorrhage, RR = rate ratio, VBAC = vaginal birth after cesarean.
↵* There were 138 836 elective repeat cesarean deliveries, 58 704 attempted VBAC deliveries, 29 261 successful VBAC deliveries and 29 443 failed VBAC deliveries. Our study was restricted to women with a parity of 1 who had a previous cesarean delivery and who delivered a singleton at 37 to 43 weeks gestation in the current pregnancy in Canada (excluding Quebec) from 2003 to 2014.
↵† Logistic models included maternal age, diabetes mellitus, hypertension and labour induction.
↵‡ Severe maternal morbidity and mortality included death, acute myocardial infarction, heart failure, pulmonary edema, disseminated intravascular coagulation, cardiac arrest, assisted ventilation, cardiac complications from anesthesia, cardiopulmonary resuscitation, adult respiratory distress syndrome, acute/unspecified renal failure, blood transfusion given PPH, shock procedures to control bleeding given PPH, cesarean hysterectomy given PPH, total hysterectomy open approach given PPH, subtotal hysterectomy open approach given PPH and repair of injury to bladder and urethra.
↵¶ Restricted severe morbidity included the same conditions as for severe maternal morbidity and mortality, except blood transfusion given PPH.