Table 2 Clinical characteristics of infants with and without ROP. Means + SD, or rate and (%), or median and (IQR)

Gestational age (wks)

26.6 ± 1.8

27.6 ± 1.5

< 0.001

Birth weight (g)

887 ± 268

1043 ± 262

< 0.001

 < 10° percentile

9 (13)

7 (6)

< 0.001

 Z-score

−0.05 ± 1.06

0.27 ± 0.87

0.874

Male

30 (44)

57 (51)

0.720

Apgar score at 5th min

8 (7–9)

8 (7–8)

0.609

Antenatal steroids

58 (87)

97 (87)

0.004

Caesarean section

48 (71)

81 (73)

0.310

 Duration (h)

27.5 (12.2–49.2)

16 (6–30)

0.002

 Duration (h)

4 (0–21)

0 (0–2)

0.029

RBC transfusions

4.4 ± 5.5

1.6 ± 2.5

< 0.001

Sildenafil

10 (15)

4 (4)

 Total dose (mg/kg)

1.68 ± 2.59

0.12 ± 0.57

< 0.001

 Duration (d)

20.1 ± 44.9

0.10 ± 0.51

< 0.001

Maternal milk (%)

40.3 ± 31.2

68.2 ± 31.1

< 0.001

Human milk (%)

9.2 ± 18.7

7.5 ± 13.2

0.477

Formula milk (%)

50.3 ± 29.6

24.1 ± 27.0

< 0.001

Weight 36 weeks of PMA (g)

1881 ± 434

1853 ± 414

0.691

 Z-score

−1.78 ± 1.20

− 1.91 ± 0.94

0.434

PDA

39 (58)

62 (56)

0.035

Sepsis

26 (39)

35 (31)

0.053

BPD

24 (36)

25 (22)

0.025

NEC

7 (10%)

3 (3%)

0.048

 1–2 grade

10 (15%)

13 (12%)

0.141

 3–4 grade

11 (16%)

9 (8%)

PVL

13 (19%)

10 (9%)

0.011

Hospital stay (d)

96.8 ± 55.4

65.0 ± 30.2

< 0.001

Mortality

4 (6%)

15 (13%)

0.156