Table 2 Perinatal characteristics of study participants

Male/Female

11/15

10/13

10/13

12/12

Gestational age at birth, weeks

26^###

(24–31)

29.5

(26–32)

40

(38–42)

40

(37–43)

Birth weight, g

960^###

(583–1510)

1470

(659–2200)

3505

(2660–4840)

3458

(2670–4550)

Small for gestational age

8 (31)

7 (30)

0

0

Maternal smoking during pregnancy

7 (27)

3 (13)

2 (9)

5 (21)

Prenatal corticosteroid therapy

11 (42)

10 (43)

N/A

N/A

Caesarean section

13 (50)

18 (78)

1 (4)

1 (4)

Multiple birth

8 (31)

12 (52)

0

0

Apgar score at 1 min

5 (1–9)***

8 (4–10)

9 (5–10)

9 (5–9)

Apgar score at 5 min

7 (3–10)***

9 (3–10)**

10 (7–10)

10 (8–10)

Instillation of surfactant

8 (31)

2 (4)

N/A

N/A

Ventilator therapy, days

4 (0–38)

0 (0–8)

N/A

N/A

CPAP, days

41 (3–70)

3 (0–19)

N/A

N/A

Supplemental O₂, days

67 (28–180)

3 (1–26)

N/A

N/A

Septicemia

16 (62)^##

6 (26)

N/A

N/A

PDA, treated

8 (31)^##

0

N/A

N/A

ROP grade 3–4

7 (27)

3 (13)

N/A

N/A