Table 1 Demographic, socioeconomic and familial factors of the study participants

n

1140

317

15

55

41

Baseline characteristics

 Caucasian ethnicity

1093 (95.8 %)

304 (96.0 %)

11 (73.3 %)

50 (90.9 %)

39 (95.1 %)

 Smoking during pregnancy

70 (6.1 %)

45 (14.2 %)

0 (0.0 %)

1 (1.8 %)

1 (2.4 %)

 Mothers’ mean age, years

31.9 (5.2)

30.0 (5.8)

31.9 (5.2)

32.0 (5.5)

31.6 (5.3)

 Fathers’ mean age, years

34.1 (5.7)

32.6 (6.4)

33.9 (5.1)

33.9 (4.5)

33.2 (4.6)

 Highest education of parents

  Low (up to 12y)

220 (19.3 %)

86 (27.2 %)

4 (26.7 %)

9 (16.4 %)

7 (17.1 %)

  Intermediate (>12 years, e.g. college)

331 (29.0 %)

96 (30.2 %)

3 (20.0 %)

19 (34.5 %)

13 (31.7 %)

  High (e.g. university)

565 (49.6 %)

121 (38.3 %)

8 (53.3 %)

27 (49.1 %)

21 (51.2 %)

 Allergies in family

  Maternal atopy (A, AR or E)

765 (67.1 %)

210 (66.4 %)

13 (86.7 %)

48 (87.3 %)

36 (87.8 %)

  Paternal atopy (A, AR or E)

610 (53.5 %)

170 (53.7 %)

11 (73.3 %)

30 (54.5 %)

23 (56.1 %)

  Maternal food hypersensitivity

249 (21.8 %)

77 (24.4 %)

6 (40.0 %)

13 (23.6 %)

11 (26.8 %)

  Paternal food hypersensitivity

135 (11.8 %)

35 (11.1 %)

1 (6.7 %)

7 (12.7 %)

6 (14.6 %)

 Urban living environment

273 (23.9 %)

99 (31.2 %)

6 (40.0 %)

11 (20.0 %)

8 (19.5 %)

 Mean number of sibs at home

1.7 (0.88)

1.8 (0.99)

1.4 (0.65)

1.6 (0.71)

1.5 (0.64)

 Female sex

557 (48.9 %)

166 (52.4 %)

6 (40.0 %)

23 (41.8 %)

17 (41.5 %)

 Animals in household at birth

  Any

566 (49.6 %)

164 (50.6 %)

8 (53.3 %)

33 (60.0 %)

26 (63.4 %)

  Cat

325 (28.5 %)

92 (28.4 %)

4 (26.6 %)

15 (27.3 %)

10 (24.4 %)

  Dog

204 (17.9 %)

66 (20.4 %)

3 (20.0 %)

15 (27.3 %)

13 (31.7 %)

 Season of birth (n = 1139)

  Summer

379 (33.3)

112 (34.6 %)

2 (13.3 %)

21 (38.2 %)

17 (41.5 %)

  Autumn

251 (22.0)

66 (20.4 %)

7 (46.6 %)

13 (23.6 %)

8 (19.5 %)

  Winter

183 (16.1)

51 (15.7)

2 (13.3 %)

9 (16.4 %)

8 (19.5 %)

  Spring

326 (28.6)

95 (29.3 %)

4 (26.6 %)

11 (20.0 %)

8 (19.5 %)