Table 1 Demographic and baseline characteristics in infants

Sex (male), n (%)

65 (51.18)

78 (62.40)

3.23

1

0.07

0.82 (0.66, 1.02)

Gestational age (weeks), mean ± SD

30.00 ± 1.83

29.65 ± 2.04

1.45

250

0.15

2.48 (−0.89, 5.85)

Birthweight(g), mean ± SD

1, 302.26 ± 209.81

1, 328.72 ± 222.17

−0.97

250

0.33

− 26.46 (−80.07, 27.15)

Small for gestational age, n (%)

22 (17.32)

18 (14.40)

0.40

1

0.53

1.20 (0.68, 2.13)

Extremely low birthweight infant, n (%)

14 (11.02)

11 (8.80)

0.35

1

0.56

1.25 (0.59, 2.65)

Sicker infants, n (%)

20 (15.75)

22 (17.60)

0.16

1

0.69

0.90 (0.52, 1.56)

Birth head circumference (cm), mean ± SD

27.16 ± 1.50

27.08 ± 1.78

0.42

250

0.68

0.09 (−0.32, 0.50)

Apgar score at 5 min, median (IQR)

9 (9-10)

9 (9-10)

7, 646.00

-^a

0.40

-^b

TRIPS score, median (IQR)

13 (8-13)

13 (8-13)

8, 848.00

-^a

0.06

-^b

NRDS, n (%)

39 (30.71)

30 (24.00)

1.43

1

0.23

1.28 (0.85, 1.92)

Pulmonary surfactant use, n (%)

37 (29.13)

30 (24.00)

0.85

1

0.36

1.21 (0.80, 1.84)

Time to start OAC/NS (h), mean ± SD

24.47 ± 11.16

23.78 ± 10.92

0.50

250

0.62

0.70 (−2.04, 3.44)

Established enteral feeding within 24 h after birth, n (%)

111 (87.40)

105 (84.00)

0.60

1

0.44

1.04 (0.94, 1.15)

Maternal age (y), mean ± SD

31.81 ± 4.51

31.83 ± 4.79

−0.03

250

0.98

−0.02 (−1.17, 1.14)

Gestational hypertension, n (%)

23 (18.11)

15 (12.00)

1.84

1

0.18

1.51 (0.83, 2.76)

Gestational diabetes mellitus, n (%)

42 (33.07)

34 (27.20)

1.03

1

0.31

1.22 (0.83, 1.78)

Antenatal steroid use, n (%)

115 (90.55)

115 (92.00)

0.17

1

0.68

0.98 (0.91, 1.06)

Antenatal magnesium sulfate use, n (%)

82 (64.57)

68 (54.40)

2.70

1

0.10

1.19 (0.97, 1.46)

Twin or multiple gestation, n (%)

48 (37.80)

42 (33.60)

0.48

1

0.49

1.13 (0.81, 1.57)

Cesarean delivery, n (%)

77 (60.63)

71 (56.80)

0.38

1

0.54

1.07 (0.87, 1.31)

Premature rupture of membranes, n (%)

50 (39.37)

60 (48.00)

1.91

1

0.17

0.82 (0.62, 1.09)

Histologic chorioamnionitis, n (%)

42 (33.07)

33 (26.40)

1.34

1

0.25

1.25 (0.85, 1.84)