One-year survival of infants delivered at 22 and at 23 weeks of gestation during 2004–2007, 2014–2016 and 2017–2019
| 22 weeks | 23 weeks | |||||
| T1 2004–2007* | T2 2014–2016 | T3 2017–2019 | T1 2004–2007* | T2 2014–2016 | T3 2017–2019 | |
| Total number | 140 | 134 | 125 | 183 | 213 | 182 |
| Stillbirths† | 91 (65) | 60 (45)‡ | 45 (36)‡ | 82 (45) | 65 (31)‡ | 67 (37) |
| Live-born infants | 49 (35) | 74 (55)‡ | 80 (64)‡ | 101 (55) | 148 (69)‡ | 115 (63) |
| Died before 1 year, total | 44/49 (90) | 45/74 (61)‡ | 49/80 (61)‡ | 48/101 (48) | 57/148 (39) | 38/115 (33) |
| ≤12 hours§ | 37/49 (76) | 27/74 (37)¶ | 23/80 (29)¶ | 27/101 (27) | 15/148 (10)‡ | 10/115 (9)‡ |
| 13 hours to 7 days | 2/49 (4) | 5/74 (7) | 11 (14) | 12/101 (12) | 12/148 (8) | 7/115 (6) |
| 8–27 days | 4/49 (8) | 11/74 (15) | 9 (11) | 7/101 (7) | 16/148 (11) | 12/115 (10) |
| 28 days to 1 year | 1/49 (2) | 2/74 (4) | 6 (8) | 2/101 (2) | 14/148 (9) | 9/115 (8) |
| One-year survival | ||||||
| All births** | 5/140 (4) | 29/134 (22)‡ | 31/125 (25)‡ | 53/183 (29) | 91/213 (43)‡ | 77/182 (42)‡ |
| Live-born infants | 5/49 (10) | 29/74 (39)‡ | 31/80 (39)‡ | 53/101 (53) | 91/148 (61) | 77/115 (67) |
| NICU admissions | 5/19 (26) | 29/50 (58) | 31/67 (46) | 53/81 (65) | 91/138 (66) | 77/110 (70) |
| One-year survival without major neonatal morbidity†† | ||||||
| Live-born infants | 1/49 (2) | 5/74 (7) | 6/74 (8) | 9/101 (9) | 23/148 (16) | 19/115 (17) |
| Infants admitted to NICU | 1/19 (5) | 5/50 (10) | 6/67 (9) | 9/81 (11) | 23/138 (17) | 19//110 (17) |
| Of survivors at 1 year | 1/5 (20) | 5/29 (17) | 6/31 (19) | 9/53 (17) | 23/91 (25) | 19/76 (25) |
Data are presented as n (%) unless otherwise indicated.
*Data are from Fellman et al. 10
†Stillbirths in T2 and T3 were identified from the Swedish Medical Birth Registry.12
‡P<0.01 for pairwise adjusted comparisons with the T1 (2004–2007).
§Difference in time categories of mortality were examined with adjusted multiple comparisons by χ2 test with post hoc analysis (Bonferroni correction).
¶P<0.001 for pairwise adjusted comparisons with the T1 (2004–2007).
**Includes stillbirths.
††Major neonatal morbidity defined as intraventricular haemorrhage grade 3 or 4, cystic periventricular leucomalacia, surgically treated necrotising enterocolitis, retinopathy of prematurity stage 3, 4 or 5 or severe bronchopulmonary dysplasia (treatment with ≥30% oxygen at 36 weeks+0 days of postmenstrual age).
NICU, neonatal intensive care unit.