Table 1.
Comparison of selected demographic data in the studied cohorts.
| Extremely preterm (23–26 weeks) (n = 41) | Very preterm (27–29 weeks) (n = 39) | Moderately preterm (30–32 weeks) (n = 33) | P | |
|---|---|---|---|---|
| Birth weight, g (x ± SD) | 727 ± 124 | 1149 ± 207 | 1245 ± 211 | <0.001a |
| Gestational age (weeks) (x ± SD) | 25.0 ± 1.1 | 28.2 ± 0.8 | 30.7 ± 0.8 | <0.001a |
| Male gender | 24 (58%) | 20 (51%) | 17 (52%) | 0.76b |
| Vaginal delivery/Cesarean section | 20/21 | 15/24 | 8/25 | 0.01b |
| Multiple pregnancy | 4 (10%) | 8 (20%) | 6 (18%) | 0.56b |
| Small-for-gestational-age infant | 4 (10%) | 1 (2%) | 5 (15%) | 0.1b |
| Maternal hypertension | 8 (19%) | 7 (18%) | 2 (8%) | 0.74b |
| Maternal diabetes | 3 (7%) | 2 (5%) | 0 | 0.79b |
| Maternal fever/infection prior to delivery | 5 (12%) | 6 (15%) | 4 (13%) | 0.8b |
| 1st minute Apgar score (Me; 25–75th percentile) | 2 (1–4) | 5 (4–6) | 5 (2–6) | 0.01c |
| 5th minute Apgar score (Me; 25–75th percentile) | 6 (4–6) | 7 (6-7) | 7 (6–8) | 0.001c |
| Delivery room intubation | 28 (69%) | 16 (40%) | 11 (33%) | 0.01b |
| Surfactant therapy | 33 (81%) | 29 (73%) | 14 (43%) | 0.003b |
| Initial a/A ratio | 0.31 ± 0.2 | 0.25 ± 0.13 | 0.44 ± 0.25 | 0.01a |
| Prenatal steroids | 10 (25%) | 12 (29%) | 22 (66%) | 0.01b |
| Ureaplasma infection | 12 (29%) | 8 (21%) | 6 (18%) | 0.28b |
| Pharmacological closure of patent ductus arteriosus | 22 (54%) | 23 (59%) | 11 (33%) | 0.08b |
| Surgical closure of patent ductus arteriosus | 18 (44%) | 4 (10%) | 2 (6%) | <0.001b |
| Length of mechanical ventilation (Me; 25–75th percentile) | 42 (25–52) | 3 (1–10) | 2 (0–6) | <0.001c |
| Bronchopulmonary dysplasia | 40 (98%) | 24 (62%) | 6 (18%) | <0.001b |
a P value for one-way analysis of variance.
b P value for chi-square test.
c P value for Kruskal-Wallis analysis of variance.