Table 1 Comparison of characteristics of mother-newborn pairs in full cohort versus subset with lymphocyte immunophenotype versus subgroup with Volatile Organic Compounds personal assessment and lymphocyte immunophenotype

Mother's age, mean ± SD, years

29.99 ± 4.89

29.77 ± 4.72

0.39

29.25 ± 3.64

0.37

19 - 24.9 (%)

11.71

9.88

0.26

3.7

0.12

25 - 34.9 (%)

70.95

74.55

87.04

> 35 (%)

17.34

15.57

9.26

BMI, mean ± SD, kg/m²

26.32 ± 4.46

25.89 ± 4.10

0.1

25.00 ± 3.37

0.13

Normal (%)

45.09

48.77

0.22

57.14

0.56

Overweight (%)

37.82

36.78

35.71

Moderate obesity (%)

12.13

11.44

5.36

Severe obesity (%)

3.69

1.91

1.79

Morbid obesity (%)

1.27

1.09

0

Employment status, %

71.23

74.12

0.17

78.57

0.48

Full-time

77.4

77.74

0.9

80

0.73

Part-time

22.6

22.26

20

Passive smoking, %

During 1^st trimester

30.68

32.25

0.47

28.57

0.58

During 2^nd trimester

28.62

28.73

0.96

25

0.56

During 3^rd trimester

26.21

25.75

0.82

25

0.91

Active smoking , %

Before pregnancy

36.28

32.97

0.1

23.21

0.14

During 1^st trimester

25.84

20.71

0.01

0

0.04

During 2^nd trimester

17.55

15.26

0.19

0

0.001

During 3^rd trimester

16.73

17.12

0.82

0

0.002

Maternal history of allergies, %

51.74

51.1

0.78

51.79

0.92

Gestational duration, mean ± SD, weeks

39.22 ± 1.75

39.41 ± 1.22

0.54

39.45 ± 1.16

0.72

< 37 weeks (%)

6.17

2.43

0.004

1.79

0. 09

≥ 37 weeks (%)

93.83

97.57

98.21

Birth weight, mean ± SD, g

3279 ± 585

3343 ± 456

0.05

3359 ± 396

0.58

< 2, 500 g (%)

10.61

2.43

< 0.0001

1.79

0.09

≥ 2, 500 g (%)

89.39

97.57

98.21

Newborn's sex , %

Male

52.55

49.19

0.15

57.14

0.27

Female

47.45

50.81

42.86

Season of birth*, %

Autumn

22.22

16.8

0.003

14.29

0.43

Winter

21.03

22.76

30.36

Spring

30.17

36.59

39.29

Summer

26.58

23.85

16.07