Table 3.
Survival to discharge for infants born at GA 22–28 weeks in NRN centers January 1, 1993 – December 31, 2012
| No./Total (%) | 1993 | 2012 | 1993–1997 | 1998–2002 | 2003–2007 | 2008–2012 |
|---|---|---|---|---|---|---|
| All infants (N=34636) | (N=1433) | (N=1922) | (N=7027) | (N=9132) | (N=9600) | (N=8877) |
| Died | 426/1433 (30) | 409/1922 (21) | 1992/7027 (28) | 2489/9132 (27) | 2725/9600 (28) | 2131/8877 (24) |
| Died within 12 h | 193/1433 (13) | 166/1922 (9) | 909/7027 (13) | 1025/9132 (11) | 1054/9600 (11) | 843/8877 (9) |
| Survived to discharge | ||||||
| All infants | 1007/1433 (70) | 1513/1922 (79) | 5035/7027 (72) | 6643/9132 (73) | 6875/9600 (72) | 6746/8877 (76) |
| 22 weeks | 5/ 79 (6) | 7/ 75 (9) | 25/ 358 (7) | 27/ 437 (6) | 25/ 421 (6) | 22/ 334 (7) |
| 23 | 34/ 122 (28) | 50/ 150 (33) | 184/ 660 (28) | 215/ 821 (26) | 226/ 873 (26) | 252/ 779 (32) |
| 24 | 85/ 163 (52) | 174/ 269 (65) | 465/ 871 (53) | 715/1273 (56) | 752/1377 (55) | 774/1241 (62) |
| 25 | 153/ 225 (68) | 249/ 308 (81) | 784/1070 (73) | 1065/1397 (76) | 1081/1503 (72) | 1077/1391 (77) |
| 26 | 208/ 250 (83) | 291/ 333 (87) | 980/1194 (82) | 1317/1542 (85) | 1322/1580 (84) | 1281/1513 (85) |
| 27 | 238/ 283 (84) | 337/ 357 (94) | 1183/1337 (88) | 1536/1720 (89) | 1615/1837 (88) | 1568/1733 (90) |
| 28 | 284/ 311 (91) | 405/ 430 (94) | 1414/1537 (92) | 1768/1942 (91) | 1854/2009 (92) | 1772/1886 (94) |
| Survival to discharge without major morbidity among all infantsa | ||||||
| All infants evaluatedb | 256/1256 (20) | 559/1895 (29) | 1096/6100 (18) | 2119/8869 (24) | 2318/9368 (25) | 2493/8723 (29) |
| 22 weeks | 0/ 79 (0) | 0/ 75 (0) | 2/ 355 (<1) | 3/ 437 (<1) | 0/ 421 (0) | 0/ 334 (0) |
| 23 | 2/ 120 (2) | 1/ 150 (<1) | 12/ 650 (2) | 9/ 820 (1) | 16/ 871 (2) | 13/ 779 (2) |
| 24 | 12/ 160 (8) | 15/ 268 (6) | 60/ 850 (7) | 77/1269 (6) | 65/1377 (5) | 87/1238 (7) |
| 25 | 33/ 208 (16) | 61/ 306 (20) | 128/1001 (13) | 198/1384 (14) | 212/1493 (14) | 237/1383 (17) |
| 26 | 52/ 213 (24) | 85/ 331 (26) | 199/1028 (19) | 371/1516 (24) | 433/1555 (28) | 413/1505 (27) |
| 27 | 69/ 242 (29) | 167/ 353 (47) | 305/1090 (28) | 628/1650 (38) | 669/1785 (37) | 735/1693 (43) |
| 28 | 88/ 234 (38) | 230/ 412 (56) | 390/1126 (35) | 833/1793 (46) | 923/1866 (49) | 1008/1791 (56) |
| Infants who survived to discharge (N=25299) | (N=1007) | (N=1513) | (N=5035) | (N=6643) | (N=6875) | (N=6746) |
| Survival to discharge without major morbidity among infants who survived to discharge | ||||||
| All survivors evaluatedc | 256/ 830 (31) | 559/1486 (38) | 1096/4108 (27) | 2119/6380 (33) | 2318/6643 (35) | 2493/6592 (38) |
| 22 weeks | 0/ 5 (0) | 0/ 7 (0) | 2/ 22 (9) | 3/ 27 (11) | 0/ 25 (0) | 0/ 22 (0) |
| 23 | 2/ 32 (6) | 1/ 50 (2) | 12/ 174 (7) | 9/ 214 (4) | 16/ 224 (7) | 13/ 252 (5) |
| 24 | 12/ 82 (15) | 15/ 173 (9) | 60/ 444 (14) | 77/ 711 (11) | 65/ 752 (9) | 87/ 771 (11) |
| 25 | 33/ 136 (24) | 61/ 247 (25) | 128/ 715 (18) | 198/1052 (19) | 212/1071 (20) | 237/1069 (22) |
| 26 | 52/ 171 (30) | 85/ 289 (29) | 199/ 814 (24) | 371/1291 (29) | 433/1297 (33) | 413/1273 (32) |
| 27 | 69/ 197 (35) | 167/ 333 (50) | 305/ 936 (33) | 628/1466 (43) | 669/1563 (43) | 735/1528 (48) |
| 28 | 88/ 207 (43) | 230/ 387 (59) | 390/1003 (39) | 833/1619 (51) | 923/1711 (54) | 1008/1677 (60) |
Major morbidity was defined as one or more of necrotizing enterocolitis, infections (early-onset sepsis, late-onset sepsis, or meningitis), BPD, severe ICH, PVL, and ROP stage ≥ 3.
Of the 34,636 infants in the cohort, 1576 (4.6%) could not be evaluated for survival without major morbidity due to missing information for one or more morbidity. More than half of those missing information were infants born 1993–1997. During this period, BPD and PVL were most frequently missing; PVL was missing when a cranial sonogram was not performed at ≥ 2 weeks. During 1998–2012, ROP was most frequently missing because no examination was completed prior to discharge. Proportions are among the 33,060 infants who could be evaluated, including infants who died within 12 hours of life.
Proportions are among 23,723 of 25,299 infants who survived to discharge, excluding 1576 infants who survived but could not be evaluated for major morbidity due to missing information.