Table 2.
Descriptive data for the perinatal variables for cases of childhood-onset type 1 diabetes and controls, and univariate ORs and 95% CIs, adjusted for the case–control design
| Variable | Cases | Controls | OR (95% CI) |
|---|---|---|---|
| Overall | |||
| Caesarean section | 1853/14,948 (0.12) | 6303/55,707 (0.11) | 1.11 (1.05, 1.18) |
| Birthweight (g) | 3563 ± 538 | 3550 ± 549 | 1.00 (1.00, 1.00) |
| Gestational age (days) | 279 ± 12 | 279 ± 12 | 0.99 (0.99, 0.99) |
| Gestational lengtha | |||
| Very preterm | 40/14,922 (0.0027) | 269/55,615 (0.0048) | 0.56 (0.40, 0.79) |
| Moderate to late preterm | 845/14,922 (0.0566) | 2530/55,615 (0.0455) | 1.26 (1.16, 1.37) |
| Full term | 14,037/14,922 (0.941) | 52,816/55,615 (0.950) | – |
| Age of mother (years) | 28.60 ± 5.12 | 28.32 ± 5.10 | 1.01 (1.01, 1.01) |
| Birthweight z score | 0.077 ± 1.08 | –0.017 ± 1.08 | 1.08 (1.06, 1.10) |
| Boys | |||
| Caesarean section | 1007/7925 | 3332/28,638 | 1.11 (1.01, 1.22) |
| Birthweight (g) | 3626 ± 547 | 3615 ± 555 | 1.00 (1.00, 1.00) |
| Gestational age (days) | 279 ± 12 | 280 ± 12 | 0.99 (0.99, 1.00) |
| Gestational lengtha | |||
| Very preterm | 19/7908 (0.002) | 132/28,592 (0.0046) | 0.39 (0.22, 0.69) |
| Moderate to late preterm | 458/7908 (0.058) | 1368/28,592 (0.048) | 1.17 (1.02, 1.33) |
| Full term | 7431/7908 (0.940) | 27,277/28,592 (0.954) | – |
| Age of mother (years) | 28.66 ± 5.11 | 28.36 ± 5.11 | 1.01 (1.00, 1.02) |
| Birthweight z score | 0.23 ± 1.08 | 0.13 ± 1.07 | 1.08 (1.05, 1.10) |
| Girls | |||
| Caesarean section | 846/7023 | 2971/27,069 | 1.08 (0.98, 1.20) |
| Birthweight (g) | 3492 ± 519 | 3483 ± 535 | 1.00 (1.00, 1.00) |
| Gestational age (days) | 279 ± 12 | 279 ± 12 | 0.99 (0.99, 0.99) |
| Gestational lengtha | |||
| Very preterm | 20/7013 (0.003) | 131/27,018 (0.0048) | 0.80 (0.46, 1.40) |
| Moderate to late preterm | 387/7013 (0.055) | 1161/27,018 (0.043) | 1.24 (1.08, 1.44) |
| Full term | 6606/7013 (0.942) | 25,726/27,018 (0.952) | – |
| Age of mother (years) | 28.54 ± 5.12 | 28.28 ± 5.10 | 1.01 (1.00, 1.02) |
| Birthweight z score | –0.09 ± 1.05 | –0.17 ± 1.06 | 1.06 (1.03, 1.10) |
Data are n (proportion) or means ± SD
aVery preterm <224 days, moderate to late preterm 224–258 days, full term ≥259 days