Table 2 Comparison of perinatal and clinical data of VPIs without infection-related morbidities

GA, [M(Q1,Q3)], weeks

31.2 (30.3,31.7)

30.6 (29.8,31.6)

30.2 (29.1,31.1)^a,b

52.165

< 0.001

BW, [M(Q1,Q3)], grams

1510 (1300,1720)

1460 (1220,1630)

1340 (1160,1560)^a,b

31.253

< 0.001

Multiple gestation, n(%)

42 (27.6)

111 (29.7)

455 (34.8)

5.701

0.058

Male gender, n(%)

67 (44.1)

216 (57.8) ^a

718 (54.9)^a

8.333

0.016

Cesarean section, n(%)

94 (61.8)

245 (65.5)

831 (63.5)

0.765

0.682

SGA, n(%)

18 (11.8)

44 (11.8)

143 (10.9)

0.276

0.871

Apgar score ≤ 7 at 5 min, n(%)

15 (9.9)

19 (5.1)

131 (10.0)^b

8.805

0.012

PROM > 18 hours, n(%)

13 (8.6)

53 (14.2)

207 (15.8)

5.875

0.053

Completed antenatal steroids^c, n(%)

75 (49.3)

174 (46.5)

607 (46.4)

0.476

0.788

Gestational diabetes mellitus, n(%)

32 (21.1)

59 (15.8)

235 (18.0)

2.173

0.337

Gestational hypertension, n(%)

27 (17.8)

75 (20.1)

221 (16.9)

2.001

0.368

Postnatal corticosteroid use, n(%)

3 (2.0)

14 (3.7)

285 (21.8)^a,b

99.163

<0.001

Duration of mechanical ventilationd, [M(Q1,Q3)], days

7.4 (2.9,15.0)

8.1 (3.0,19.7)

16.0 (7.0,30.0)^a,b

89.815

<0.001

Length of hospital stay, [M(Q1,Q3)], days

33.0 (24.0,42.0)

36.0 (29.0,46.0)^a

44.0 (34.0,57.0)^a,b

111.334

<0.001