Perinatal and early neonatal characteristics treatments of infants less than 25 weeks estimated gestational age in the Neonatal Research Network in group I (birth from 1 January 1991 to 31 December 1994) and group II (birth 1 January 1995 to 31 December 1998)
| Group I (n = 1408) | Group II (n = 1348) | p Value | |
|---|---|---|---|
| ANS, Antenatal steroid treatment; ROM, rupture of membranes before delivery; Surfactant, any surfactant given at any time; NS, not significant by χ2 test; significance was assigned at p<0.05. | |||
| ANS | 13.4 | 54.6 | <0.0001 |
| Complete ANS | 7.4 | 31.4 | <0.0001 |
| Antenatal antibiotics | 39.2 | 67.8 | <0.0001 |
| ROM >24 h | 26.0 | 26.8 | NS |
| Multiple gestation | 17.1 | 19.4 | NS |
| Caesarean section | 19.5 | 26.3 | <0.0001 |
| Apgar ⩽3 at 1 min | 72.7 | 62.5 | <0.0001 |
| Apgar ⩽3 at 5 min | 39.4 | 35.1 | 0.02 |
| Surfactant | 58.2 | 68.6 | <0.0001 |