TABLE 1.
Demographic and Antenatal Characteristics
| Characteristic | All Infants (N = 24 896) | No BPD (n = 12 198) | Grade 1–2 BPD (n = 9192) | Grade 3 BPD (n = 932) | Died Before 36 wk PMA (n = 2574) |
|---|---|---|---|---|---|
| Gestational age, wk | |||||
| Mean ± SD | 27.1 ± 2 | 28 ± 1.5 | 26.5 ± 1.8 | 25.7 ± 1.8 | 25 ± 1.8 |
| 22 + 0/7 to 22 + 6/7, n (%) | 313 | 14 (4.5) | 103 (32.9) | 31 (9.9) | 165 (52.7) |
| 23 + 0/7 to 23 + 6/7, n (%) | 1580 | 100 (6.3) | 713 (45.1) | 118 (7.5) | 649 (41.1) |
| 24 + 0/7 to 24 + 6/7, n (%) | 2474 | 365 (14.8) | 1273 (51.5) | 195 (7.9) | 641 (25.9) |
| 25 + 0/7 to 25 + 6/7, n (%) | 2967 | 802 (27.0) | 1538 (51.8) | 210 (7.1) | 417 (14.1) |
| 26 + 0/7 to 26 + 6/7, n (%) | 3292 | 1274 (38.7) | 1596 (48.5) | 136 (4.1) | 286 (8.7) |
| 27 + 0/7 to 27 + 6/7, n (%) | 3940 | 2127 (54.0) | 1503 (38.1) | 110 (2.8) | 200 (5.1) |
| 28 + 0/7 to 28 + 6/7, n (%) | 4853 | 3256 (67.1) | 1387 (28.6) | 89 (1.8) | 121 (2.5) |
| 29 + 0/7 to 29 + 6/7, n (%) | 5477 | 4260 (77.8) | 1079 (19.7) | 43 (0.8) | 95 (1.7) |
| Birth wt, mean ± SD, g | 964 ± 304 | 1112 ± 269 | 866 ± 263 | 738 ± 229 | 691 ± 226 |
| Small for gestational age,a n (%) | 2294 (9.2) | 482 (4.0) | 1102 (12.0) | 199 (21.5) | 511 (20.3) |
| Male sex, n (%) | 12 965 (52.1) | 5953 (48.8) | 4988 (54.3) | 539 (57.8) | 1485 (57.7) |
| Multiple gestation, n (%) | 5660 (22.7) | 2859 (23.4) | 1984 (21.6) | 203 (21.8) | 614 (23.9) |
| Maternal race and/or ethnicity, n (%) | |||||
| Black non-Hispanic | 7966 (32.0) | 4046 (33.5) | 2692 (29.5) | 366 (39.6) | 862 (33.9) |
| White non-Hispanic | 9860 (39.6) | 4639 (38.4) | 3836 (42.1) | 364 (39.4) | 1021 (40.2) |
| Hispanic | 4913 (19.7) | 2435 (20.1) | 1889 (20.7) | 131 (14.2) | 458 (18) |
| Other | 1399 (5.6) | 691 (5.7) | 521 (5.7) | 36 (3.9) | 151 (5.9) |
| Antenatal steroids, n (%) | 21 848 (88.8) | 10 787 (88.8) | 8171 (89.3) | 823 (89.0) | 2067 (80.8) |
| Vaginal delivery, n (%) | 7260 (29.2) | 3726 (30.6) | 2518 (27.4) | 235 (25.2) | 781 (30.4) |
All percentage values were calculated among infants with complete data for the described variable. Data shown in the table were missing in <1% of study infants.
a
Small for gestational age was defined as a birth wt for gestational age and sex <10% per the Fenton growth curves.16