Univariate analysis: perinatal variables significantly associated with chronic lung disease (CLD) 1998–1999
| Perinatal variable | CLD/total | Unadjusted OR (95% CI) | p Value | Missing data |
|---|---|---|---|---|
| *Birth weight for gestational age groups 75th–89th, 90th–96th, ⩾97th were combined because ORs were similar. | ||||
| OR, Odds ratio; CI, confidence interval. ROM, rupture of membranes; IUGR, intrauterine growth restriction. | ||||
| Maternal ethnicity | 0.002 | 505 | ||
| White | 955/4163 (23%) | 1.00 reference group | ||
| Asian | 71/331 (21%) | 0.92 (0.70 to 1.20) | ||
| Indigenous Australian | 51/243 (21%) | 0.89 (0.65 to 1.23) | ||
| Maori | 15/116 (13%) | 0.50 (0.29 to 0.86) | ||
| Pacific Islander | 35/241 (15%) | 0.57 (0.40 to 0.82) | ||
| Previous perinatal death | 89/316 (28%) | 1.41 (1.09 to 1.82) | 0.01 | 708 |
| Hypertension in pregnancy (any) | 298/1224 (24%) | 1.18 (1.02 to 1.37) | 0.03 | 63 |
| Antepartum haemorrhage | 315/1276 (25%) | 1.21 (1.04 to 1.40) | 0.01 | 483 |
| Preterm prelabour ROM | 249/1283 (19%) | 0.81 (0.70 to 0.95) | 0.008 | 0 |
| Suspected IUGR | 193/663 (29%) | 1.56 (1.30 to 1.87) | <0.0001 | 79 |
| Gestational age | <0.0001 | 0 | ||
| 31 weeks | 59/1343 (4%) | 1.00 reference group | ||
| 30 weeks | 83/1056 (8%) | 1.86 (1.32 to 2.62) | ||
| 29 weeks | 141/916 (15 %) | 3.96 (2.88 to 5.43) | ||
| 28 weeks | 159/737 (22%) | 5.99 (4.37 to 8.20) | ||
| 27 weeks | 202/554 (36%) | 12.49 (9.13 to 17.08) | ||
| 26 weeks | 228/463 (49%) | 21.11 (15.36 to 29.02) | ||
| 25 weeks | 193/300 (64%) | 39.25 (27.60 to 55.81) | ||
| ⩽24 weeks | 170/230 (74%) | 61.65 (41.60 to 91.36) | ||
| Weight for gestational age | <0.0001 | 0 | ||
| ⩾75th* | 173/1256 (14%) | 0.65 (0.54 to 0.79) | ||
| 25th–74th | 575/2930 (20%) | 1.00 reference group | ||
| 10th–24th | 257/864 (30%) | 1.73 (1.46 to 2.06) | ||
| 3rd–9th | 146/376 (39%) | 2.60 (2.07 to 3.26) | ||
| <3rd | 84/173 (49%) | 3.87 (2.83 to 5.28) | ||
| Sex | <0.0001 | 0 | ||
| Female | 497/2526 (20%) | 1.00 reference group | ||
| Male | 738/3073 (24%) | 1.28 (1.14 to 1.47) | ||
| Presentation | <0.0001 | 632 | ||
| Cephalic | 667/3314 (20%) | 1.00 reference group | ||
| Breech | 354/1390 (25%) | 1.36 (1.17 to 1.57) | ||
| Other | 75/263 (29%) | 1.58 (1.20 to 2.10) | ||
| Delivery | 0.01 | 156 | ||
| Vaginal birth | 476/2219 (21%) | 1.00 reference group | ||
| Caesarean in labour | 273/1358 (20%) | 0.92 (0.78 to 1.09) | ||
| Caesarean no labour | 454/1866 (24%) | 1.18 (1.02 to 1.36) | ||
| Apgar at 1 min <4 | 357/978 (37%) | 2.45 (2.11 to 2.85) | <0.0001 | 0 |