Table 1.
Characteristics | Frequency (percentage a) | ||
---|---|---|---|
Birth cohort sample (Years 2007 to 2010) 2254 women 2277 babies | Deliveries in region b (Years 2007 to 2010) 36620 women 37061 babies | p-value c (two-sided) | |
Maternal age | |||
< 20 years | 107 (4.8%) | 2559 (7.0%) | < 0.001 |
20-24 years | 438 (19.9%) | 6407 (17.6%) | |
25-29 years | 632 (28.6%) | 10376 (28.5%) | |
30-34 years | 560 (25.4%) | 10088 (27.7%) | |
≥ 35 years | 469 (21.3%) | 6980 (19.2%) | |
Missing data | 48 | 0 | |
Gender of infant | |||
Male | 1127 (50.3%) | 18914 (51.3%) | 0.324 |
Female | 1115 (49.7%) | 17926 (48.7%) | |
Missing data | 35 | 0 | |
Birthweight | |||
< 2500 g | 55 (2.5%) | 1800 (4.9%) | < 0.001 |
2500-3999 g | 1809 (81.5%) | 30207 (82.0%) | |
≥ 4000 g | 355 (16.0%) | 4831 (13.1%) | |
Missing data | 58 | 2 | |
Gestational age at birth | |||
28-36 weeks | 79 (3.5%) | 2376 (6.4%) | < 0.001 |
37-41 weeks | 2131 (95.9%) | 34264 (93.0%) | |
42 weeks | 13 (0.6%) | 200 (0.5%) | |
Missing data | 54 | 0 | |
Plurality | |||
Singleton | 2207 (98.0%) | 35980 (97.7%) | |
Multiple | 46 (2.0%) | 860 (2.3%) | 0.370 |
Missing data | 24 | 0 | |
Outcome | |||
Live birth | 2273 (99.8%) | 36728 (99.7%) | |
Stillbirth | 4 (0.2%) | 112 (0.3%) | 0.274 |
Missing data | 0 | 0 |
aPercentages are calculated based on the available (non-missing) data.
bData include only deliveries with gestational 28 weeks or more; data are provided by Queensland Health and New South Wales Health for the study region (Logan, Beaudesert, Gold Coast and Tweed).
cChi-square test for comparing proportions between birth cohort sample and the general population.