Comparison of maternal and infant characteristics in the two cohorts of live very preterm births by gestational age group
| Live births 24–31 weeks' gestational age | Live births 24–27 weeks' gestational age | Live births 28–31 weeks' gestational age | |||||||
|---|---|---|---|---|---|---|---|---|---|
| 1997 | 2003 | 1997 | 2003 | 1997 | 2003 | ||||
| N=488 | N=580 | p Value | N=137 | N=159 | p Value | N=351 | N=421 | p Value | |
| Population characteristics | |||||||||
| Maternal age (mean (SD)) | 30.1 (5.1) | 30.9 (6.0) | 0.02 | 30.6 (5.6) | 30.6 (6.1) | NS | 29.9 (5.5) | 31.0 (5.9) | 0.006 |
| Multiple birth (%) | 32.6 | 27.6 | 0.08 | 38.0 | 28.3 | 0.05 | 30.5 | 27.3 | NS |
| Male (%) | 53.3 | 53.0 | NS | 48.2 | 49.7 | NS | 55.3 | 54.2 | NS |
| Birth weight (mean (SD)) | 1203 (365) | 1170 (367) | NS | 850 (171) | 844 (184) | NS | 1338 (327) | 1292 (342) | 0.06 |
| Gestational age (mean (SD)) | 28.8 (2.0) | 28.7 (2.0) | NS | 26.1 (0.9) | 25.9 (1.1) | 0.08 | 29.9 (1.1) | 29.7 (1.1) | 0.03 |
| Medical complications of pregnancy | |||||||||
| Premature rupture of membranes/preterm labour (%) | 66.6 | 62.9 | NS | 81.8 | 78.6 | NS | 60.7 | 57 | NS |
| Haemorrhages (%) | 15.6 | 11.4 | 0.04 | 11.7 | 10.1 | NS | 17.1 | 12.0 | 0.04 |
| Hypertensive disease (%) | 24.2 | 23.6 | NS | 14.6 | 15.1 | NS | 27.9 | 26.8 | NS |
| Small for gestational age (%) | 32.9 | 35.5 | NS | 25.2 | 24.2 | NS | 35.9 | 39.8 | NS |