Birthweight specific SIDS mortality rates in singletons and twins
| Singletons | Twins | ||||||
|---|---|---|---|---|---|---|---|
| Birth weight | No. of SIDS | No. of live births (%) | SIDS rate per 1000 | No. of SIDS | No. of live births (%) | SIDS rate per 1000 | Twin/singleton relative risk (95% CI) |
| <1500 g | 76 | 34499 (0.9%) | 2.20 | 16 | 8991 (8.8%) | 1.78 | 0.81 (0.47 to 1.38) NS |
| 1500–2499 g | 371 | 187798 (4.9%) | 1.98 | 59 | 43534 (42.8%) | 1.36 | 0.69 (0.52 to 0.90) p<0.01 |
| 2500–2999 g | 537 | 614251 (16.1%) | 0.87 | 24 | 33546 (33.0%) | 0.72 | 0.82 (0.54 to 1.23) NS |
| 3000–3499 g | 657 | 1638506 (42.1%) | 0.40 | 15 | 12563 (12.3%) | 1.19 | 2.98 (1.79 to 4.97) p<0.0001 |
| ≥3500 g | 456 | 1287181 (3.4%) | 0.35 | 1 | 1753 (1.7%) | 0.57 | 1.61 (0.23 to 11.45) NS |
| Not stated | 35 | 42992 (1.1%) | 0.81 | 0 | 1392 (1.4%) | 0 | |
| All birth weights | 2132 | 3805227 (100%) | 0.56 | 115 | 101779 (100%) | 1.13 | 2.12 (1.75 to 2.55) p<0.0001 |