Mortality, antenatal and perinatal characteristics of infants born < 29 weeks according to period of steroid exposure
| Characteristic | No steroid (n=319) | <24 h steroids (n=677) | OR (95% CI) | p Value | Complete course (n=1281) | OR (95% CI) | p Value | No steroid+<24 hrs (n=996) | Complete course + >7 days (1553) | OR (95% CI) | p Value |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Mortality (n=2549) | 96 (30.1) | 184 (27.2) | 0.87 (0.65 to 1.16) | 0.379 | 214 (16.7) | 0.47 (0.35 to 0.62) | <0.001 | 280 (28.1) | 266 (17.1) | 0.53 (0.44 to 0.64) | <0.001 |
| Maternal age, years | 28.0 (23.0–32.0) | 29.0 (24.0–33.0) | – | 0.042 | 30.0 (26.0–34.0) | – | <0.001 | 28.0 (23.0–33.0) | 30.0 (25.0–34.0) | – | <0.001 |
| Aboriginal ethnicity | 28 (8.8) | 51 (7.5) | 0.85 (0.52 to 1.37) | 0.581 | 50 (3.9) | 0.42 (0.26 to 0.68) | <0.001 | 79 (7.9) | 62 (4.0) | 0.48 (0.34 to 0.68) | <0.001 |
| Assisted conception | 31 (9.7) | 66 (9.7) | 1.00 (0.64 to 1.57) | 1.000 | 197 (15.4) | 1.69 (1.13 to 2.52) | 0.012 | 97 (9.7) | 225 (14.5) | 1.57 (1.22 to 2.02) | <0.001 |
| Pregnancy-induced hypertension | 21 (6.6) | 78 (11.5) | 1.85 (1.12 to 3.05) | 0.021 | 255 (19.9) | 3.53 (2.22 to 5.61) | <0.001 | 99 (9.9) | 280 (18.0) | 1.99 (1.56 to 2.55) | <0.001 |
| Chorioamnionitis* | 31/176 (17.6) | 84/414 (20.3) | 1.19 (0.75 to 1.88) | 0.524 | 155/713 (21.7) | 1.30 (0.85 to 1.99) | 0.271 | 115/590 (19.5) | 219/880 (24.9) | 1.37 (1.06 to 1.77) | 0.018 |
| Vaginal breech | 66 (20.7) | 81 (12.0) | 0.52 (0.36 to 0.74) | <0.001 | 120 (9.4) | 0.40 (0.28 to 0.55) | <0.001 | 147 (14.8) | 142 (9.1) | 0.58 (0.45 to 0.74) | <0.001 |
| Born in non-tertiary centre | 140 (43.9) | 98 (14.5) | 0.22 (0.16 to 0.29) | <0.001 | 16 (1.2) | 0.02 (0.01 to 0.03) | <0.001 | 238 (23.9) | 23 (1.5) | 0.05 (0.03 to 0.07) | <0.001 |
| Apgar score <7 at 5 minutes† | 127/304 (41.8) | 212/674 (31.5) | 0.64 (0.48 to 0.85) | 0.002 | 246/1278 (19.2) | 0.33 (0.25 to 0.43) | <0.001 | 339/978 (34.7) | 305/1547 (19.7) | 0.46 (0.39 to 0.56) | <0.001 |
| Male gender | 176 (55.2) | 373 (55.1) | 1.00 (0.76 to 1.30) | 1.000 | 699 (54.6) | 0.98 (0.76 to 1.25) | 0.895 | 549 (55.1) | 845 (54.4) | 0.97 (0.83 to 1.14) | 0.756 |
| Gestational age, weeks | 26.0 (25.0–28.0) | 26.0 (25.0–27.0) | – | 0.444 | 27.0 (25.0–28.0) | – | 0.012 | 26.0 (25.0–28.0) | 27.0 (25.0–28.0) | – | <0.001 |
| Birth weight, grams | 895 (730–1090) | 926 (740–1100) | – | 0.449 | 900 (721.5–1080.0) | – | 0.788 | 912.5 (740.0–1095.8) | 914.0 (731.0–1095.0) | – | 0.746 |
| Birth weight <10th % | 27 (8.5) | 58 (8.6) | 1.01 (0.63 to 1.63) | 0.947 | 166 (13.0) | 1.61 (1.05 to 2.47) | 0.035 | 85 (8.5) | 187 (12.0) | 1.47 (1.12 to 1.92) | 0.006 |
| Surfactant therapy | 273 (85.6) | 529 (78.1) | 0.60 (0.42 to 0.86) | 0.007 | 885 (69.1) | 0.38 (0.27 to 0.53) | <0.001 | 802 (80.5) | 1055 (67.9) | 0.51 (0.42 to 0.62) | <0.001 |
| Mechanical ventilation | 305 (95.6) | 623 (92.0) | 0.53 (0.29 to 0.97) | 0.050 | 1091 (85.2) | 0.26 (0.15 to 0.46) | <0.001 | 928 (93.2) | 1312 (84.5) | 0.40 (0.30 to 0.53) | <0.001 |
| Duration of ventilation, days | 5.5 (2.0–17.0) | 5 (2.0–13.8) | – | 0.315 | 6.0 (2.0–20.0) | – | 0.222 | 5.0 (2.0–15.0) | 6.0 (2.0–19.0) | – | 0.023 |
| Patent ductus arteriosus requiring treatment | 142 (44.5) | 325 (48.0) | 1.15 (0.88 to 1.50) | 0.336 | 512 (40.0) | 0.83 (0.65 to 1.06) | 0.157 | 467 (46.9) | 594 (38.2) | 0.70 (0.60 to 0.82) | <0.001 |
| Proven systemic infection | 100 (31.3) | 218 (32.2) | 1.04 (0.78 to 1.39) | 0.844 | 498 (38.9) | 1.39 (1.07 to 1.81) | 0.015 | 318 (31.9) | 594 (38.2) | 1.32 (1.12 to 1.56) | 0.001 |
| Intraventricular haemorrhage grade 3 or 4† | 53/284 (18.7) | 131/644 (20.3) | 1.11 (0.78 to 1.59) | 0.616 | 99/1230 (8.0) | 0.38 (0.27 to 0.55) | <0.001 | 184/928 (19.8) | 120/1486 (8.1) | 0.36 (0.28 to 0.45) | <0.001 |
| Chronic lung disease | 84 (26.3) | 168 (24.8) | 0.92 (0.68 to 1.25) | 0.663 | 425 (33.2) | 1.39 (1.06 to 1.83) | 0.023 | 252 (25.3) | 509 (32.8) | 1.44 (1.21 to 1.72) | <0.001 |
| Postnatal steroid for CLD | 67 (21.0) | 127 (18.8)` | 0.87 (0.62 to 1.21) | 0.454 | 320 (25.0) | 1.25 (0.93 to 1.69) | 0.158 | 194 (19.5) | 383 (24.7) | 1.35 (1.11 to 1.64) | 0.003 |
| Home oxygen | 36 (11.3) | 81 (12.0) | 1.07 (0.70 to 1.62) | 0.837 | 225 (17.6) | 1.68 (1.15 to 2.44) | 0.009 | 117 (11.7) | 259 (16.7) | 1.50 (1.19 to 1.90) | <0.001 |
| Length of intensive care stay, days. | 73 (11–92) | 70 (27.0–92.0) | – | 0.919 | 75.5 (59.0–96.0) | – | 0.002 | 71.0 (16.3–92.0) | 75.0 (59.0–96.0) | – | <0.001 |
Data are presented as n (%) (OR, 95%, CI) or median (IQR). No steroid infant group or no steroid+ <24hrs coverage groups set as referent for OR and 95% CI calculation. OR denotes odds ratio. aChorioamnionitis including clinically suspected cases, denominator is number of total followed up from 2001 onwards. bDenominator is the number of infants examined; data unavailable in some cases.