Table 6.
Composite adverse perinatal outcome 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 | 552/579 | 95 | 460/468 | 98 | 0.97 | (0.95‐0.99) |
| 28‐31 wk GA | 695/846 | 82 | 426/513 | 83 | 0.99 | (0.94‐1.04) |
| 32‐36 wk GA | 1015/4911 | 21 | 733/3936 | 19 | 1.11 | (1.02‐1.21) |
| 37‐42 wk GA | 2489/73 106 | 3.4 | 1972/70 774 | 2.8 | 1.22 | (1.15‐1.30) |
| Birthweight p10‐p90 (normal weight) | ||||||
| 25‐27 wk GA | 1249/1382 | 90 | 1017/1130 | 90 | 1.00 | (0.98‐1.03) |
| 28‐31 wk GA | 3209/4654 | 69 | 2456/3694 | 66 | 1.04 | (1.01‐1.07) |
| 32‐36 wk GA | 4654/41 665 | 11 | 3315/32 951 | 10 | 1.11 | (1.06‐1.16) |
| 37‐42 wk GA | 10 778/671 723 | 1.6 | 7981/640 051 | 1.2 | 1.29 | (1.25‐1.32) |
| Birthweight ≥p90 (LGA) | ||||||
| 25‐27 wk GA | 139/163 | 85 | 170/192 | 89 | 0.96 | (0.89‐1.05) |
| 28‐31 wk GA | 327/486 | 67 | 272/441 | 62 | 1.09 | (0.99‐1.21) |
| 32‐36 wk GA | 334/2667 | 13 | 264/2655 | 10 | 1.26 | (1.08‐1.47) |
| 37‐42 wk GA | 1893/93 090 | 2.0 | 1408/90 754 | 1.6 | 1.31 | (1.22‐1.40) |
| All birthweights | ||||||
| 25‐27 wk GA | 1940/2124 | 91 | 1647/1790 | 92 | 0.99 | (0.97‐1.01) |
| 28‐31 wk GA | 4231/5986 | 71 | 3154/4648 | 68 | 1.04 | (1.02‐1.07) |
| 32‐36 wk GA | 6003/49 243 | 12 | 4312/39 542 | 11 | 1.12 | (1.08‐1.16) |
| 37‐42 wk GA | 15 160/837 919 | 1.8 | 11 361/801 579 | 1.4 | 1.28 | (1.25‐1.31) |
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 are all neonates with perinatal death (antepartum or intrapartum/neonatal death) or morbidity in each stratum and the denominator all deliveries in each birthweight category.