Table 1 Demographics and characteristics of eligible neonates

Gender, male, n (%)

177 (59.8)

161 (60.3)

16 (55.2)

0.74 ^a

Birth weight (kg), median (IQR)

2.9 (2.2, 3.3)

2.9 (2.2, 3.3)

2.8 (2.0, 3.1)

0.30 ^b

 Very low birth weight (< 1.5 kg)

24 (8.1)

20 (7.5)

4 (13.8)

0.27 ^c

Weight at surgery (kg), median (IQR)

2.9 (2.2, 3.3)

2.9 (2.2, 3.3)

2.9 (2.4, 3.2)

0.85 ^b

Gestational age (days), median (IQR)

266.0 (245.0, 274.0)

266.0 (245.0, 274.0)

258.0 (244.0, 274.0)

0.49 ^b

 Gestational weeks (< 37), n (%)

127 (10.0)

112 (8.2)

15 (17.2)

0.42 ^a

 Gestational weeks (37 ≥), n (%)

169 (90.0)

155 (91.8)

14 (82.8)

Age at the surgery (days), median (IQR)

6.0 (4.0, 12.0)

6.0 (4.0, 11.0)

6.0 (4.0, 16.0)

0.25 ^b

ASA

0.91 ^c

 I

1 (0.3)

1 (0.4)

0 (0.0)

 II

83 (28.0)

76 (28.5)

7 (24.1)

 III

191 (64.5)

171 (64.0)

20 (69.0)

 IV

21 (7.1)

18 (7.1)

2 (6.9)

Preoperative hemoglobin (g/dl), mean ± SD

147.2 ± 45.3

147.5 ± 45.8

144.0 ± 41.2

0.90 ^b

Preoperative blood transfusion, n (%)

46 (15.5)

38 (14.2)

8 (27.6)

0.11 ^a