Proportions and associations of short-term infant outcomes with induction of labour for non-medical reasons, stratified for gestational age groups 37–41 weeks, New South Wales, Australia 2001–2016 (n=4 74 652)
| Spontaneous onset of labour proportion N (%) | Induction for non- medical reasons Proportion n (%) | AOR* (99% CI) | |
| Admission to NICU | |||
| 37+0–37+6 | 2408 (12.8) | 454 (14.4) | 1.16 (1.00 to 1.34) |
| 38+0–38+6 | 3808 (6.9) | 971 (7.8) | 1.18 (1.07 to 1.30) |
| 39+0–39+6 | 6746 (5.7) | 1197 (5.9) | 1.08 (0.99 to 1.18) |
| 40+0–40+6 | 9283 (5.9) | 1739 (6.0) | 1.00 (0.93 to 1.07) |
| 41+0–41+6 | 3973 (7.1) | 351 (7.4) | 1.01 (0.87 to 1.17) |
| Asphyxia | |||
| 37+0–37+6 | 165 (0.9) | 42 (1.3) | 1.64 (1.04 to 2.58) |
| 38+0–38+6 | 422 (0.8) | 126 (1.0) | 1.37 (1.04 to 1.79) |
| 39+0–39+6 | 989 (0.8) | 193 (1.0) | 1.18 (0.96 to 1.45) |
| 40+0–40+6 | 1601 (1.0) | 336 (1.2) | 1.09 (0.93 to 1.28) |
| 41+0–41+6 | 699 (1.2) | 79 (1.7) | 1.22 (0.89 to 1.66) |
| Apgar score <4 | |||
| 37+0–37+6 | 24 (0.1) | 6 (0.2) | 1.63 (0.50 to 5.31) |
| 38+0–38+6 | 51 (0.1) | 9 (0.1) | 0.85 (0.33 to 2.18) |
| 39+0–39+6 | 111 (0.1) | 16 (0.1) | 0.79 (0.38 to 1.65) |
| 40+0–40+6 | 132 (0.1) | 31 (0.1) | 1.28 (0.76 to 2.17) |
| 41+0–41+6 | 66 (0.1) | 8 (0.2) | 1.30 (0.49 to 3.43) |
| Birth trauma | |||
| 37+0–37+6 | 591 (3.1) | 124 (3.9) | 1.34 (1.03 to 1.75) |
| 38+0–38+6 | 1578 (2.9) | 434 (3.5) | 1.34 (1.15 to 1.54) |
| 39+0–39+6 | 3593 (3.0) | 705 (3.5) | 1.20 (1.08 to 1.34) |
| 40+0–40+6 | 5279 (3.4) | 1130 (3.9) | 1.08 (0.99 to 1.17) |
| 41+0–41+6 | 2346 (4.2) | 226 (4.7) | 0.99 (0.82 to 1.19) |
| Resuscitation | |||
| 37+0–37+6 | 3997 (21.3) | 723 (22.9) | 1.06 (0.94 to 1.20) |
| 38+0–38+6 | 11 002 (20.0) | 3518 (28.4) | 1.46 (1.37 to 1.55) |
| 39+0–39+6 | 25 346 (21.3) | 5252 (26.0) | 1.21 (1.16 to 1.27) |
| 40+0–40+6 | 42 190 (27.0) | 9005 (31.2) | 1.15 (1.11 to 1.19) |
| 41+0–41+6 | 16 635 (29.5) | 1461 (30.6) | 1.00 (0.91 to 1.08) |
| Major resuscitation | |||
| 37+0–37+6 | 849 (4.5) | 206 (6.5) | 1.48 (1.20 to 1.83) |
| 38+0–38+6 | 2065 (3.8) | 631 (5.1) | 1.38 (1.22 to 1.56) |
| 39+0–39+6 | 4871 (4.1) | 1005 (5.0) | 1.22 (1.11 to 1.33) |
| 40+0–40+6 | 7703 (4.9) | 1771 (6.1) | 1.23 (1.15 to 1.33) |
| 41+0–41+6 | 3317 (5.9) | 363 (7.6) | 1.26 (1.08 to 1.46) |
| Respiratory disorders | |||
| 37+0–37+6 | 1180 (6.3) | 282 (8.9) | 1.43 (1.19 to 1.71) |
| 38+0–38+6 | 2129 (3.9) | 631 (5.1) | 1.33 (1.17 to 1.50) |
| 39+0–39+6 | 4200 (3.5) | 798 (3.9) | 1.15 (1.04 to 1.27) |
| 40+0–40+6 | 6221 (4.0) | 1154 (4.0) | 0.98 (0.90 to 1.07) |
| 41+0–41+6 | 2736 (4.9) | 253 (5.3) | 1.03 (0.86 to 1.23) |
Associations in bold are statistically significant p<0.01.
*Adjusted for maternal characteristics (ie, maternal age, country of birth, socioeconomic position, parity).
aOR, adjusted OR; NICU, neonatal intensive care unit.