Risk of neonatal mortality in non-malformed singleton term infants born 1983–2006, by gestational week at birth and birth weight for gestational age (GA) (n=2 152 738)
| Neonatal mortality | |||||
| Live births (n) | Deaths (n) | Crude (n=882) | Adjusted model 1* (n=882) | Adjusted model 2† (n=705) | |
| OR (95% CI) | OR (95% CI) | OR (95% CI) | |||
| Gestational week | |||||
| 37 | 98 326 | 86 | 2.62 (2.03 to 3.37) | 2.49 (1.93 to 3.21) | 1.73 (1.29 to 2.31) |
| 38 | 241 277 | 103 | 1.28 (1.01 to 1.62) | 1.26 (0.99 to 1.60) | 0.86 (0.65 to 1.13) |
| 39 | 448 264 | 133 | 0.89 (0.71 to 1.11) | 0.89 (0.71 to 1.10) | 0.84 (0.66 to 1.08) |
| 40 | 595 569 | 199 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 41 | 451 257 | 186 | 1.23 (1.01 to 1.51) | 1.22 (1.00 to 1.49) | 1.20 (0.96 to 1.50) |
| 42+ | 310 806 | 175 | 1.69 (1.38 to 2.07) | 1.59 (1.30 to 1.95) | 1.36 (1.08 to 1.71) |
| Birth weight for GA percentile | |||||
| <3 | 62 635 | 81 | 3.51 (2.76 to 1.40) | 3.23 (2.54 to 4.10) | 2.54 (1.93 to 3.33) |
| 3–<10 | 151 558 | 98 | 1.75 (1.40 to 2.19) | 1.69 (1.35 to 2.11) | 1.58 (1.23 to 2.02) |
| 10 to <25 | 321 184 | 119 | 1.00 (0.82 to 1.23) | 0.99 (0.81 to 1.21) | 1.01 (0.81 to 1.27) |
| 25–75 | 1 074 943 | 397 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| >75–90 | 321 668 | 95 | 0.80 (0.64 to 1.00) | 0.81 (0.64 to 1.01) | 0.74 (0.57 to 0.95) |
| >90–97 | 150 183 | 58 | 1.05 (0.79 to 1.38) | 1.05 (0.80 to 1.38) | 0.91 (0.66 to 1.25) |
| >97 | 63 328 | 34 | 1.45 (1.02 to 2.06) | 1.44 (1.01 to 2.04) | 1.36 (0.93 to 1.98) |
↵* Model 1 adjusts for year of birth and birth weight percentiles or gestational week.
↵† Model 2 additionally adjusts for mother's country of birth, education level, age, parity, smoking status in early pregnancy, pre-eclampsia, premature rupture of membranes, diagnosis of hypertension or diabetes, mode of delivery, year of delivery and infant's sex.