Table 5.
Composite neonatal morbidity rate in males and females by birthweight percentiles and gestational age category
| Male infants | Female infants | RRa | (95% CI) | |||
|---|---|---|---|---|---|---|
| (n = 895 272) | % | (n = 847 559) | % | |||
| Birthweight <p10 (SGA) | ||||||
| 25‐27 wk GA | 94/121 | 78 | 48/56 | 86 | 0.91 | (0.78‐1.05) |
| 28‐31 wk GA | 324/475 | 68 | 190/277 | 69 | 0.99 | (0.90‐1.10) |
| 32‐36 wk GA | 535/4431 | 12 | 366/3569 | 10 | 1.18 | (1.04‐1.33) |
| 37‐42 wk GA | 1723/72 340 | 2.4 | 1320/70 122 | 1.9 | 1.27 | (1.18‐1.36) |
| Birthweight p10‐p90 (normal weight) | ||||||
| 25‐27 wk GA | 674/807 | 84 | 527/807 | 82 | 1.01 | (0.97‐1.06) |
| 28‐31 wk GA | 2602/4047 | 64 | 1861/3099 | 60 | 1.07 | (1.03‐1.11) |
| 32‐36 wk GA | 3754/40 765 | 9.2 | 2550/32 186 | 7.9 | 1.16 | (1.11‐1.22) |
| 37‐42 wk GA | 9292/670 237 | 1.4 | 6533/638 603 | 1.0 | 1.36 | (1.31‐1.40) |
| Birthweight ≥p90 (LGA) | ||||||
| 25‐27 wk GA | 87/111 | 78 | 105/127 | 83 | 0.95 | (0.84‐1.08) |
| 28‐31 wk GA | 248/407 | 60 | 197/366 | 54 | 1.13 | (1.00‐1.28) |
| 32‐36 wk GA | 274/2607 | 11 | 213/2604 | 8.2 | 1.28 | (1.08‐1.52) |
| 37‐42 wk GA | 1698/92 895 | 1.8 | 1233/90 579 | 1.4 | 1.34 | (1.25‐1.44) |
| All birthweights | ||||||
| 25‐27 wk GA | 855/1039 | 82 | 680/823 | 83 | 0.99 | (0.95‐1.04) |
| 28‐31 wk GA | 3174/4929 | 64 | 2248/3742 | 60 | 1.07 | (1.04‐1.11) |
| 32‐36 wk GA | 4563/47 803 | 9.5 | 3129/38 359 | 8.2 | 1.17 | (1.12‐1.22) |
| 37‐42 wk GA | 12 713/835 472 | 1.5 | 9086/799 304 | 1.1 | 1.34 | (1.30‐1.37) |
Abbreviations: CI, confidence interval; GA, gestational age; LGA, large‐for‐gestational age; RR, relative risk ratio; SGA, small‐for‐gestational age.
a
RR calculated as: the numerator is all alive neonates with morbidity in each stratum and the denominator all alive neonates in each birthweight category.