Table 3: Distribution of infant characteristics by BPD status.

CharacteristicsAll infantsBPD
Cases 𝑛 = 6 4 Controls 𝑛 = 4 8 𝑃 OR*95% CI

Sex, 𝑛 (%)
 Male108 (50.9)34 (53.1)74 (50.0)0.6761.100.731.66
 Female104 (49.1)30 (46.9)74 (50.0)1.00
Gestational age, 𝑛 (%)
 27–29 weeks114 (53.8)40 (62.5)74 (50.0)0.0941.430.932.20
 30-31 weeks98 (46.2)24 (37.5)74 (50.0)1.00
Birth weight, 𝑛 (%)
 <1000 g37 (17.4)14 (21.9)23 (15.5)0.3011.700.863.38
 1000–1500 g130 (61.3)40 (62.5)90 (60.8)1.300.762.53
 >1500 g45 (21.2)10 (15.6)35 (23.6)1.00
SGA 𝑛 (%)12 (5.7)3 (4.7)9 (6.1)0.6870.820.302.23
Apgar score <5 at 5 min, 𝑛 (%)2 (0.94)0 (0.0)2 (1.35)0.3501.000.821.21
Mean SNAP II, 𝑛 (%)
 0 to 10143 (67.4)102 (68.9)41 (64.0)
 11 to 1954 (5.5)36 (24.3)18 (28.1)0.381
 >2015 (7.1)10 (6.8)5 (7.2)
PDA (%)64 (30.2)30 (46.9)34 (23.0)0.0012.041.383.03
Air Leak Syndrome (%)12 (5.7)6 (9.4)6 (4.0)0.1241.720.943.16
Sepsis (%)109 (51.4)39 (60.9)70 (47.3)0.0681.470.982.38
IVH grade III or IV (%)4 (1.90)1 (1.6)3 (2.0)0.8200.830.154.56
Ventilatory Support (%)
 nCPAP only162 (76.4)37 (57.8)125 (84.5)0.0001
 nCPAP + MV50 (23.6)27 (42.2)23 (15.5)2.361.613.46
LOMV ≥ 7 days (%)*15 (30.0)*8 (29.6)7 (30.4)1.120.681.84
Use of Surfactant (%)
 Very early106 (50.0)20 (31.2)86 (58.1)0.0001
 Rescue27 (12.7)18 (28.1)9 (6.1)6.162.5315.02
 No surfactant79 (37.3)26 (40.6)53 (35.8)3.532.195.69
FIO2 (median values)0.530.520.520.102

Deaths before 36 wPMA are excluded. BPD: bronchopulmonary dysplasia, SGA: small for gestational age, SNAP-II: score for neonatal acute physiology, nCPAP: nasal continuous positive airway pressure, MV: mechanical ventilation, LOMV: length of mechanical ventilation, PDA: patent ductus arteriosus.