Table 3. Cesarean section and rate of subsequent stillbirth, miscarriage, or ectopic pregnancy.
| Outcome by Mode of Deliverya | Crude Model HR (95% CI) | Adjusted HR (95% CI) | ||
| Model 1b | Model 2c | Model 3d | ||
| Stillbirth ( n = 1,996 events) | ||||
| Spontaneous vaginal (n = 1,399) | Ref | Ref | Ref | Ref |
| Operative vaginal (n = 172) | 1.03 (0.88, 1.20) | 1.06 (0.90, 1.25) | 1.03 (0.88, 1.22) | 1.05 (0.89, 1.23) |
| All cesarean sectionse (n = 425) | 1.17 (1.05, 1.30) | 1.25 (1.12, 1.39) | 1.20 (1.07, 1.34) | 1.14 (1.01, 1.28) |
| Emergency cesarean (n = 305) | 1.19 (1.05, 1.34) | 1.25 (1.11, 1.42) | 1.21 (1.06, 1.37) | 1.15 (1.01, 1.31) |
| Elective cesarean* (n = 120) | 1.12 (0.93, 1.35) | 1.23 (1.02, 1.49) | 1.18 (0.97, 1.43) | 1.11 (0.91, 1.35) |
| Miscarriage ( n = 73,406 events) | ||||
| Spontaneous vaginal (n = 53,540) | Ref | Ref | Ref | Ref |
| Operative vaginal (n = 7,105) | 1.09 (1.07, 1.12) | 1.03 (1.01, 1.06) | 1.02 (1.00, 1.05) | 1.02 (1.00, 1.05) |
| All cesarean sectionse (n = 12,761) | 0.94 (0.92, 0.95) | 0.94 (0.92, 0.96) | 0.98 (0.96, 1.00) | 0.98 (0.96, 1.00) |
| Emergency cesarean (n = 9,178) | 0.95 (0.93, 0.98) | 0.96 (0.94, 0.98) | 0.99 (0.97, 1.01) | 0.99 (0.96, 1.01) |
| Elective cesarean (n = 3,453) | 0.89 (0.86, 0.92) | 0.90 (0.87, 0.93) | 0.96 (0.93, 0.99) | 0.95 (0.92, 0.98) |
| Maternally requested cesarean (n = 130) | 0.68 (0.58, 0.81) | 0.69 (0.58, 0.82) | 0.72 (0.60, 0.85) | 0.72 (0.60, 0.85) |
| Ectopic pregnancy ( n = 11,877 events) | ||||
| Spontaneous vaginal (n = 8,599) | Ref | Ref | Ref | Ref |
| Operative vaginal (n = 996) | 0.96 (0.90, 1.03) | 1.02 (0.95, 1.09) | 1.02 (0.95, 1.09) | 1.03 (0.96, 1.10) |
| All cesarean sectionse (n = 2,282) | 1.03 (0.98, 1.08) | 1.07 (1.02, 1.12) | 1.09 (1.03, 1.14) | 1.09 (1.04, 1.15) |
| Emergency cesarean (n = 1,605) | 1.03 (0.97, 1.08) | 1.06 (1.00, 1.12) | 1.07 (1.02, 1.13) | 1.09 (1.03, 1.15) |
| Elective cesarean (n = 653) | 1.03 (0.95, 1.11) | 1.09 (1.00, 1.18) | 1.12 (1.03, 1.21) | 1.12 (1.03, 1.21) |
| Maternally requested cesarean (n = 24) | 0.89 (0.60, 1.33) | 0.97 (0.65, 1.46) | 1.02 (0.68, 1.53) | 1.02 (0.68, 1.53) |
Data available from 1982–2010 (cohort size = 832,996 women).
Number of events of the outcome of interest for each mode of delivery in parentheses.
Model 1: adjusted for maternal age; maternal origin; previous stillbirth, miscarriage, or ectopic pregnancy; mother's marital status; birth year; and measures of socio-economic status including mother's educational attainment and mother's and father's gross income.
Model 2: adjusted for Model 1 plus medical complications in the first live birth including delivery type (singleton versus twins or more), diabetes, gestational diabetes, placental abruption, placenta praevia, and hypertensive disorders (including eclampsia and preeclampsia).
Model 3: adjusted for Model 2 plus gestational age and birth weight.
All emergency, elective, and maternally requested cesarean sections (where applicable, i.e., from 2002–2010) combined.
*Where the number of events was less than ten for maternally requested cesarean, these were combined with the elective cesarean group for analyses.