Table 1 Sample characteristics

Parental age in years, mean (SD) *

35.2 (5.7)

33.4 (4.6)

37.9 (6.2)

Child’s age at follow-up in months, median (range) *

8 (5–35)

8 (5–35)

9.5 (5–26)

Average educational level of parents per couple, median (range) *

Low (1–3.5), n (%)

Intermediate (4–5.5), n (%)

High (6–7), n (%)

Missing, n (%)

6 (4.5–7)

0 (0)

15 (19.0)

19 (24.1)

45 (57.0)

6 (4.5 – 7)

0 (0)

10 (21.3)

11 (23.4)

26 (55.3)

6 (5–7)

0 (0)

5 (15.6)

8 (25.0)

19 (59.4)

Number of parents with a country of birth other than the Netherlands per couple, n (%)

0

1

Missing

25 (31.6)

9 (11.4)

45 (57.0)

16 (34.1)

5 (10.6)

26 (55.3)

9 (28.1)

4 (12.5)

19 (59.4)

Employment status per couple, n (%)

0

1

2

Missing

9 (11.4)

17 (21.5)

6 (7.6)

47 (59.5)

5 (10.6)

12 (25.5)

3 (6.4)

27 (57.4)

4 (12.5)

5 (15.6)

3 (9.4)

20 (62.5)

Number of responses per follow-up moment, n (%)

0.5 year

1 year

2 years

40 (50.6)

22 (27.8)

17 (21.5)

24 (51.1)

12 (25.5)

11 (23.4)

16 (50.0)

10 (31.3)

6 (18.7)

Child’s type of malformations, n (%)

Esophageal Atresia

Abdominal wall defects

Hirschsprung disease

Anorectal Malformations

26 (32.9)

13 (16.5)

22 (27.8)

18 (22.8)

15 (31.9)

9 (19.1)

12 (25.5)

11 (23.4)

11 (34.3)

4 (12.5)

10 (31.3)

7 (21.9)