Table 1 Demographic changes of the study population from 1996 to 2008
Year | 1996-2008 | 1996 | 2000 | 2004 | 2008 | ||||
|---|---|---|---|---|---|---|---|---|---|
Characteristics | No. (%) | p-value 1996-2000 | No. (%) | p-value 2000-2004 | No. (%) | p-value 2004-2008 | No. (%) | p-value 1996-2008 | |
Very preterm infants1 | 2665 (86.2) | 606 (84.2) | 0.07 | 674 (87.1) | 0.24 | 662 (87.8) | 0.04 | 723 (85.9) | 0.23 |
Very low birth weight infants2 | 425 (13.8) | 114 (15.8) | 0.03 | 100 (12.9) | 0.57 | 92 (12.2) | 0.09 | 119 (14.1) | 0.18 |
Small for gestational age3 | 576 (18.6) | 146 (20.3) | 0.06 | 136 (17.6) | 0.90 | 134 (17.8) | 0.36 | 460 (19.0) | 0.35 |
Gender | |||||||||
- female | 1507 (48.8) | 342 (47.5) | 0.11 | 390 (50.4) | 0.22 | 363 (48.1) | 0.65 | 412 (48.9) | 0.41 |
- male | 1583 (51.2) | 378 (52.5) | 384 (49.6) | 391 (51.9) | 430 (51.1) | ||||
Location of birth | |||||||||
- inborn4 | 2806 (90.8) | 622 (86.4) | 0.07 | 686 (88.6) | < 0.001 | 711 (94.3) | 0.30 | 787 (93.5) | < 0.001 |
- outborn | 284 (9.2) | 98 (13.6) | 88 (11.4) | 43 (5.7) | 55 (6.5) | ||||
Mode of delivery5 | |||||||||
- spontaneous | 567 (18.3) | 174 (24.2) | < 0.001 | 143 (18.5) | 0.24 | 127 (16.8) | 0.09 | 123 (14.6) | < 0.001 |
- caesarean section | 2395 (77.5) | 521 (72.4) | < 0.01 | 595 (76.9) | < 0.01 | 610 (80.9) | 0.29 | 669 (79.5) | < 0.001 |
Number of infants | |||||||||
- singleton | 2144 (69.4) | 541 (75.1) | < 0.01 | 546 (70.5) | 0.13 | 513 (68.0) | 0.03 | 544 (64.6) | < 0.001 |
- multiples | 946 (30.6) | 179 (24.9) | 228 (29.5) | 241 (32.0) | 298 (35.4) | ||||
Characteristics | p0.5 (p0.05-p0.95) | Mean | p-value 1996-2000 | Mean | p-value 2000-2004 | Mean | p-value 2004-2008 | Mean | p-value 1996-2008 |
Gestational age (week) | 30 0/7 (25 0/7 - 33 5/7) | 29 6/7 | < 0.01 | 29 3/7 | 1 | 29 3/7 | 0.35 | 29 4/7 | 0.04 |
Birth weight (g) | 1225 (630 - 1840) | 1238 | 0.13 | 1209 | 0.56 | 1220 | 0.51 | 1208 | 0.11 |