Table 4.
Outcome of second pregnancy | Induced abortion versus live birth | Induced abortion versus miscarriage | |||
Induced abortion | Live birth | Miscarriage | |||
Outcome of third pregnancy | N=30 527 | N=125 855 | N=22 404 | Crude and adjusted (Adj.) RR (99% CI)* | |
Live birth | 18 562 (60.8) | 85 014 (67.5) | 17 745 (79.2) | Crude 0.90 (0.89 to 0.91) | Crude 0.77 (0.76 to 0.78) |
Adj. 0.88 (0.87 to 0.89) | Adj. 0.77 (0.76 to 0.78) | ||||
Stillbirth | 84 (0.3) | 426 (0.3) | 69 (0.3) | Crude 0.81 (0.60 to 1.11) | Crude 0.89 (0.59 to 1.36) |
Adj. 0.76 (0.55 to 1.06) | Adj. 0.86 (0.54 to 1.37) | ||||
Miscarriage | 2005 (6.6) | 8778 (7.0) | 2869 (12.8) | Crude 0.94 (0.89 to 1.00) | Crude 0.51 (0.48 to 0.55) |
Adj. 0.93 (0.88 to 1.00) | Adj. 0.67 (0.62 to 0.72) | ||||
Ectopic pregnancy | 339 (1.1) | 1064 (0.9) | 181 (0.8) | Crude 1.31 (1.12 to 1.54) | Crude 1.38 (1.09 to 1.74) |
Adj. 1.31 (1.11 to 1.56) | Adj. 1.16 (0.90 to 1.50) | ||||
Induced abortion | 9537 (31.2) | 30 573 (24.3) | 1540 (6.9) | Crude 1.29 (1.25 to 1.32) | Crude 4.55 (4.25 to 4.86) |
Adj. 1.33 (1.30 to 1.37) | Adj. 4.37 (4.06 to 4.70) | ||||
Outcomes in ongoing pregnancies | N=18 646 | N=85 440 | N=17 814 | Crude and adjusted (Adj.) RR (99% CI)† | |
Pre-eclampsia | 144 (0.8) | 567 (0.7) | 165 (0.9) | Crude 1.16 (0.92 to 1.48) | Crude 0.83 (0.62 to 1.12) |
Adj. 1.40 (1.10 to 1.79) | Adj. 0.91 (0.66 to 1.27) | ||||
Placenta praevia | 183 (1.0) | 473 (0.6) | 133 (0.8) | Crude 1.77 (1.42 to 2.22) | Crude 1.32 (0.98 to 1.76) |
Adj. 1.78 (1.40 to 2.25) | Adj. 1.34 (0.97 to 1.84) | ||||
Abruptio placenta | 91 (0.5) | 325 (0.4) | 66 (0.4) | Crude 1.28 (0.95 to 1.74) | Crude 1.32 (0.87 to 2.00) |
Adj. 1.28 (0.93 to 1.77) | Adj. 1.32 (0.83 to 2.10) | ||||
Induction of labour‡ | 4298 (23.1) | 18 239 (21.4) | 3968 (22.3) | Crude 1.08 (1.04 to 1.12) | Crude 1.03 (0.98 to 1.09) |
Adj. 1.11 (1.07 to 1.16) | Adj. 1.01 (0.96 to 1.07) | ||||
Low birth weight <2500§ | 1086 (5.8) | 3905 (4.6) | 784 (4.4) | Crude 1.28 (1.17 to 1.39) | Crude 1.32 (1.17 to 1.49) |
Adj. 1.36 (1.21 to 1.51) | Adj. 1.04 (0.90 to 1.21) | ||||
Outcomes in spontaneous births | N=12 868 | N=59 220 | N=12 056 | ||
Spontaneous preterm birth <37 weeks | 859 (6.7) | 3035 (5.1) | 644 (5.3) | Crude 1.30 (1.18 to 1.43) | Crude 1.25 (1.10 to 1.42) |
Adj. 1.27 (1.14 to 1.40) | Adj. 1.14 (0.99 to 1.32) | ||||
Spontaneous very preterm birth <32 weeks | 162 (1.3) | 495 (0.8) | 104 (0.9) | Crude 1.51 (1.19 to 1.90) | Crude 1.46 (1.06 to 2.01) |
Adj. 1.44 (1.12 to 1.84) | Adj. 1.35 (0.93 to 1.96) |
Values are n (%) unless otherwise specified. Statistically significant relative risks are shown in bold.
Adjusted for age, year of delivery, Carstairs at second pregnancy and interpregnancy interval.
Adjusted for maternal age, year of pregnancy, Carstairs category at second pregnancy and interpregnancy interval.
Further adjusted for pre-eclampsia, placenta praevia and abruptio placenta.
Low birth weight also adjusted for gestational age.