Table 2 Characteristics of mothers and newborns in the entire cohort (n = 2002) vs. the study population (n = 1140)

Mothers

 Center, %

  Poitiers

48.35

55.26

  Nancy

51.65

44.74

0.0002

 Age (years) mean ± SD

29.99 ± 4.89

30.59 ± 4.71

0.10

  < 25, %

15.08

11.07

  25–34, %

68.99

70.74

  > 34, %

15.93

18.19

0.04

 BMI (kg/m²), mean ± SD

26.32 ± 4.46

26.28 ± 4.47

0.69

  Normal, %

45.09

46.09

  Overweight, %

37.82

37.03

  Moderately obese, %

12.13

11.55

  Severely obese, %

4.96

5.33

0.94

 Level of education, %

  Primary and below

7.56

4.54

  Secondary

61.05

59.34

  University and above

31.40

36.12

0.005

 Household income, %

  > 3000 euros/month

25.82

29.47

0.03

  Active smoking before pregnancy, %

36.72

30.93

0.001

 Smoking during pregnancy (active + passive), %

31.92

22.54

0.0001

 Maternal atopy

30.55

31.13

0.74

 Supplementation with vitamins and/or trace minerals, %

  During the year preceding pregnancy only

5.87

5.87

  During the 3rd trimester of pregnancy only

49.70

49.10

  During both periods

21.50

22.20

  Never

22.94

22.83

0.98

 Duration of gestation (WA), mean ± SD

39.22 ± 1.75

39.22 ± 1.75

0.97

Newborns

 Sex (girl), %

47.45

46.67

0.67

 Birth weight (kg), mean ± SD

3.28 ± 0.59

3.29 ± 0.52

0.67

 Premature, %^‡

5.77

6.05

0.75

 Number of older siblings, %

  0

48.60

48.25

  1–2

46.95

47.63

  ≥ 3

4.45

4.12

0.88

 Birth season, %

  Summer

26.58

26.14

  Autumn

22.22

22.54

  Winter

21.03

22.28

  Spring

30.17

29.04

0.82

  Exclusive breastfeeding ≥ 4 months, %

13.39

15.09

0.20