Table 1 Patient characteristics and bivariate analysis of perinatal risk factors for BPD or death*

Gestational age, weeks

31.86 [28.29-32.86]

29.29 [25.86-32.29]

0.41 (0.31-0.55)

<0.001

Birth weight, g

1570 [900–2320]

1330 [670–2100]

0.81 (0.72-0.90)^a

<0.001^b

Gender, male/female

67/35

37/21

1.09 (0.55-2.13)

0.809

Small for gestational age (<10%), n (%)

12 (11.8)

9 (15.5)

1.38 (0.54-3.50)

0.500

Apgar score, 1 min

8 [1-10]

7 [1-10]

0.90 (0.77-1.04)

0.139

Apgar score, 5 min

9 [3-10]

8.5 [2-10]

0.76 (0.63-0.93)

0.007^c

SNAP

8 [3-26]

13 [4-27]

1.28 (1.16-1.41)^d

<0.001^c

Apnea of prematurity, n (%)

12 (11.8)

18 (31.0)

3.23 (1.42-7.33)

0.005^b

Patent ductus arteriosus, n (%)

1 (1.0)

8 (13.8)

16.33 (1.99-134.2)

<0.001^c

Respiratory distress syndrome, n (%)

45 (44.1)

50 (86.2)

8.89 (3.68-21.49)

<0.001^c

Hypoxic-ischemic brain damage, n (%)

7 (6.9)

2 (3.4)

0.49 (0.10-2.43)

0.382

Intraventricular hemorrhage, n (%)

0 (0)

3 (5.2)

3E + 009

0.999

Early-onset sepsis, n (%)

4 (3.9)

2 (3.4)

0.88 (0.16-4.97)

0.887

Respiratory support^e

2.95 (1.89-4.61)

<0.001^c

Oxygen therapy, n (%)

85 (83.3)

57 (98.3)

9.39 (1.20-73.39)

0.033^b

CPAP, n (%)

45 (44.1)

30 (51.7)

1.16 (0.60-2.25)

0.659

Mechanical ventilation, n (%)

21 (20.6)

33 (56.9)

4.97 (2.45-10.08)

<0.001^c

Surfactant, n (%)

35 (34.3)

46 (79.3)

7.12 (3.34-15.17)

<0.001^c

Postnatal steroid, n (%)

23 (22.5)

20 (34.5)

1.81 (0.89-3.69)

0.104

Antenatal steroid, n (%)

11 (10.8)

5 (8.6)

0.78 (0.26-2.36)

0.658

Pre-eclampsia, n (%)

14 (13.7)

7 (12.1)

0.86 (0.33-2.28)

0.766

Premature rupture of the membranes (>24 h), n (%)

14 (13.7)

10 (17.2)

1.31 (0.54-3.17)

0.550