Participant data flow
| Era of birth | ||||||
| 1991–92 | 1997 | 2005 | ||||
| EP | Control | EP | Control | EP | Control | |
| Live births free of lethal anomalies 22–27 weeks’ gestational age—n | 428 | 255 | 217 | 195 | 270 | 219 |
| Survived to 8 years—n (% live births) | 225 (53%) | 253 (99%) | 151 (70%) | 195 (100%) | 170 (63%) | 218 (99%) |
| Utility data available—n (% survivors) | 196 (87%) | 214 (85%) | 135 (89%) | 169 (85%) | 144 (86%) | 187 (86%) |
EP, extremely preterm.