Total number of births, mean maternal age, prevalence of smoking, crude prevalence of GDM, and multivariate logistic regression analysis OR for GDM, by risk factors, for all births 1995–2005
| Risk factor . | n (% all births) . | Mean age (years) . | % smoking . | Crude prevalence GDM (%) . | Adjusted OR for GDM (95% CI)* . |
|---|---|---|---|---|---|
| Age-group | |||||
| <20 years | 42,752 (4.5) | 18.8 | 43.2 | 1.2 | 0.60 (0.54–0.67) |
| 20–24 years† | 152,150 (16.0) | 23.0 | 29.5 | 1.8 | 1.00 |
| 25–29 years | 289,635 (30.5) | 27.8 | 17.4 | 2.9 | 1.68 (1.61–1.76) |
| 30–34 years | 299,743 (31.5) | 32.3 | 12.4 | 4.2 | 2.53 (2.42–2.64) |
| 35–39 years | 139,582 (14.7) | 36.8 | 11.7 | 6.4 | 3.97 (3.80–4.16) |
| >40 years | 26,875 (2.8) | 41.3 | 11.1 | 9.8 | 6.13 (5.79–6.49) |
| Region of country of birth | |||||
| Australia and New Zealand† | 715,200 (75.2) | 29.4 | 21.7 | 2.7 | 1.00 |
| Northeast and Southeast Asia | 84,497 (8.9) | 31.6 | 2.0 | 9.4 | 3.24 (3.16–3.34) |
| Europe and North America | 62,924 (6.6) | 32.5 | 11.5 | 3.7 | 1.21 (1.16–1.26) |
| Middle East and North Africa | 38,005 (4.0) | 29.0 | 8.9 | 6.4 | 2.40 (2.30–2.51) |
| South Asia | 17,266 (1.8) | 30.0 | 0.9 | 10.5 | 4.22 (4.01–4.44) |
| Pacific | 16,763 (1.8) | 30.1 | 9.9 | 8.2 | 2.94 (2.78–3.11) |
| Other Africa | 8,281 (0.9) | 31.6 | 5.6 | 4.4 | 1.62 (1.46–1.80) |
| Caribbean, Central and South America | 7,811 (0.8) | 31.0 | 6.2 | 5.3 | 1.82 (1.65–2.01) |
| Quartiles of socioeconomic status | |||||
| 1 (highest)† | 237,488 (25.0) | 32.2 | 7.5 | 3.1 | 1.00 |
| 2 | 230,825 (24.3) | 29.9 | 15.8 | 4.1 | 1.54 (1.50–1.59) |
| 3 | 240,633 (25.3) | 28.7 | 22.4 | 4.0 | 1.74 (1.69–1.80) |
| 4 (lowest) | 241,801 (25.4) | 28.2 | 25.7 | 3.9 | 1.65 (1.60–1.70) |
| Previous pregnancies >20 weeks | |||||
| None† | 391,766 (41.2) | 28.1 | 15.3 | 3.4 | 1.00 |
| 1 | 321,035 (33.8) | 30.3 | 15.9 | 3.7 | 0.90 (0.88–0.92) |
| ≥2 | 237,408 (25.0) | 32.1 | 24.8 | 4.5 | 0.95 (0.93–0.98) |
| Risk factor . | n (% all births) . | Mean age (years) . | % smoking . | Crude prevalence GDM (%) . | Adjusted OR for GDM (95% CI)* . |
|---|---|---|---|---|---|
| Age-group | |||||
| <20 years | 42,752 (4.5) | 18.8 | 43.2 | 1.2 | 0.60 (0.54–0.67) |
| 20–24 years† | 152,150 (16.0) | 23.0 | 29.5 | 1.8 | 1.00 |
| 25–29 years | 289,635 (30.5) | 27.8 | 17.4 | 2.9 | 1.68 (1.61–1.76) |
| 30–34 years | 299,743 (31.5) | 32.3 | 12.4 | 4.2 | 2.53 (2.42–2.64) |
| 35–39 years | 139,582 (14.7) | 36.8 | 11.7 | 6.4 | 3.97 (3.80–4.16) |
| >40 years | 26,875 (2.8) | 41.3 | 11.1 | 9.8 | 6.13 (5.79–6.49) |
| Region of country of birth | |||||
| Australia and New Zealand† | 715,200 (75.2) | 29.4 | 21.7 | 2.7 | 1.00 |
| Northeast and Southeast Asia | 84,497 (8.9) | 31.6 | 2.0 | 9.4 | 3.24 (3.16–3.34) |
| Europe and North America | 62,924 (6.6) | 32.5 | 11.5 | 3.7 | 1.21 (1.16–1.26) |
| Middle East and North Africa | 38,005 (4.0) | 29.0 | 8.9 | 6.4 | 2.40 (2.30–2.51) |
| South Asia | 17,266 (1.8) | 30.0 | 0.9 | 10.5 | 4.22 (4.01–4.44) |
| Pacific | 16,763 (1.8) | 30.1 | 9.9 | 8.2 | 2.94 (2.78–3.11) |
| Other Africa | 8,281 (0.9) | 31.6 | 5.6 | 4.4 | 1.62 (1.46–1.80) |
| Caribbean, Central and South America | 7,811 (0.8) | 31.0 | 6.2 | 5.3 | 1.82 (1.65–2.01) |
| Quartiles of socioeconomic status | |||||
| 1 (highest)† | 237,488 (25.0) | 32.2 | 7.5 | 3.1 | 1.00 |
| 2 | 230,825 (24.3) | 29.9 | 15.8 | 4.1 | 1.54 (1.50–1.59) |
| 3 | 240,633 (25.3) | 28.7 | 22.4 | 4.0 | 1.74 (1.69–1.80) |
| 4 (lowest) | 241,801 (25.4) | 28.2 | 25.7 | 3.9 | 1.65 (1.60–1.70) |
| Previous pregnancies >20 weeks | |||||
| None† | 391,766 (41.2) | 28.1 | 15.3 | 3.4 | 1.00 |
| 1 | 321,035 (33.8) | 30.3 | 15.9 | 3.7 | 0.90 (0.88–0.92) |
| ≥2 | 237,408 (25.0) | 32.1 | 24.8 | 4.5 | 0.95 (0.93–0.98) |
Adjusted for all other variables in table.
Reference category.