Table 3 Characteristics of participants and non-participants born very preterm or with extremely low birthweight

Male, n

27 (43%)

47 (55%)

Cohort 1 born 1982-85, n (%)

23 (37%)

26 (31%)

Cohort 2 born 1991-92, n (%)

19 (30%)

16 (19%)

Cohort 3 born 1999–2020, n (%)

21 (33%)

43 (51%)

BW, grams, mean (SD)

948 (216)

896 (179)

0.1^a

GA, weeks, mean (SD)

27 (2)

27 (2)

1.0^b

Days on ventilator, mean (SD)

8 (9)

8 (11)

0.4^b

Days on CPAP, mean (SD)

33 (14)

29 (20)

0.3^a

Days on O₂-supplement, mean (SD)

52 (35)

57 (45)

0.4^b

Maternal smoking, n (%)

21 (34%) (n = 62)

29 (37%) (n = 77)

1.0^b

Moderat/severe BPD, n (%)

21 (33%)

37 (44%)

0.8^b

Pre-natal steroid treatment, n (%)

35 (55%)

48 (56%)

1.0^b

Post-natal steroid treatment, n (%)

14 (22%)

20 (24%)

1.0^b

Surfactant, n (%)

28 (44%)

43 (50%)

1.0^b