Table 2

Caffeine intake according to maternal characteristics

Characteristic

Category

n

%

Total caffeine, mg/day

Coffee caffeine, mg/day

Tea caffeine, mg/day


Median (IQR)

P valuea

Median (IQR)

P valuea

Median (IQR)

P valuea


Total

-

59,123

100

57 (23 to 121)

-

7 (0 to 69)

-

5 (1 to 29)

-

Maternal age, years

<25

6,688

11

34 (15 to 81)

0 (0 to 14)

3 (0 to 15)

25 to 29

20,354

34

47 (19 to 102)

<10-246

5 (0 to 46)

<10-246

5 (1 to 22)

<10-246

30 to 34

25,213

43

68 (27 to 134)

11 (0 to 83)

6 (1 to 34)

>34

6,868

12

91 (39 to 171)

30 (1 to 124)

7 (2 to 38)

Parity

0

30,393

51

47 (19 to 103)

6 (0 to 49)

5 (1 to 23)

1

18,686

32

66 (26 to 133)

<10-92

8 (0 to 81)

<10-92

6 (1 to 32)

<10-36

2

8,135

14

82 (31 to 163)

12 (0 to 101)

6 (1 to 35)

≥3

1,873

3

94 (34 to 181)

17 (0 to 138)

5 (0 to 34)

Missing

36

0.1

58 (22 to 142)

-

8 (0 to 98)

-

7 (0 to 30)

-

Marital statusb

Yes

56,941

96

57 (23 to 120)

0.004

7 (0 to 69)

0.89

5 (1 to 29)

<10-13

No

2,182

4

60 (21 to 146)

6 (0 to 79)

3 (0 to 20)

Pre-pregnancy BMI, kg/m2

<18.5

1,835

3

69 (27 to 145)

8 (0 to 81)

7 (2 to 37)

18.5 to 24.9

39,834

67

62 (25 to 129)

<10-183

9 (0 to 79)

<10-119

6 (1 to 33)

<10-237

25 to 29.9

12,444

21

51 (20 to 107)

5 (0 to 58)

5 (1 to 24)

≥30

5,01

8

39 (14 to 84)

2 (0 to 32)

2 (0 to 13)

Maternal education, years

≤12

17,925

30

55 (21 to 128)

4 (0 to 66)

3 (0 to 19)

13 to 16

24,782

42

54 (22 to 114)

<10-34

7 (0 to 64)

<10-124

6 (1 to 29)

<10-276

≥17

15,201

26

65 (27 to 125)

14 (0 to 79)

7 (2 to 37)

Missing

1,215

2

60 (22 to 124)

-

7 (0 to 69)

-

5 (0 to 28)

-

History of preterm delivery

No

57,121

97

57 (22 to 121)

<10-6

7 (0 to 68)

0.91

5 (1 to 29)

0.29

Yes

1,928

3

69 (25 to 141)

7 (0 to 80)

6 (1 to 32)

Missing

74

0.1

47 (19 to 102)

-

12 (0 to 84)

-

5 (1 to 22)

-

Smoking habits

Never

54,136

92

54 (21 to 113)

7 (0 to 61)

6 (1 to 30)

Occasionally

1,569

3

109 (42 to 201)

<10-226

44 (0 to 163)

<10-226

3 (0 to 21)

<10-101

Daily

3,085

5

143 (57 to 260)

70 (0 to 198)

2 (0 to 14)

Missing

333

1

69 (24 to 127)

-

10 (0 to 79)

-

6 (0 to 34)

-

Passive smoking

No

51,931

88

56 (22 to 118)

<10-24

7 (0 to 67)

0.08

6 (1 to 30)

<10-53

Yes

6,082

10

66 (24 to 153)

7 (0 to 86)

3 (0 to 19)

Missing

1,11

2

61 (22 to 139)

-

7 (0 to 84)

-

5 (0 to 26)

-

Nicotine other than cigarettes

No

58,552

99

57 (22 to 120)

<10-52

7 (0 to 68)

<10-49

5 (1 to 29)

0.06

Yes

571

1

138 (57 to 221)

89 (4 to 178)

4 (0 to 27)

Alcohol consumption, units/week

No alcohol

52,47

89

53 (21 to 114)

6 (0 to 60)

5 (1 to 28)

<0.5

5,579

9

93 (44 to 168)

<10-90

39 (4 to 118)

<10-90

8 (2 to 37)

<10-90

≥0.5

1,074

2

126 (67 to 216)

73 (13 to 173)

15 (2 to 39)

Nausea during second trimester

No

52,567

89

59 (24 to 125)

<10-83

8 (0 to 74)

<10-167

5 (1 to 29)

<10-10

Yes

6,556

11

43 (16 to 97)

0 (0 to 21)

4 (0 to 28)

Partners with income of >300,000 NOK/year

0

16,327

28

49 (19 to 113)

4 (0 to 54)

4 (0 to 24)

1

24,483

41

56 (22 to 120)

<10-72

6 (0 to 66)

<10-152

5 (1 to 28)

<10-81

2

16,746

28

68 (28 to 129)

14 (0 to 83)

6 (2 to 34)

Missing

1,567

3

57 (21 to 131)

-

5 (0 to 65)

-

4 (0 to 24)

-

Baby's sex

Male

30,049

51

58 (23 to 122)

0.13

7 (0 to 70)

0.7

5 (1 to 29)

0.62

Female

29,074

49

57 (22 to 120)

7 (0 to 68)

5 (1 to 29)

Quartiles of energy intake, MJ

<7.90

14,781

25

42 (15 to 96)

4 (0 to 46)

3 (0 to 21)

7.90 to 9.35

14,78

25

53 (21 to 112)

<10-72

7 (0 to 66)

<10-75

5 (1 to 28)

<10-99

9.36 to 11.14

14,782

25

61 (25 to 126)

8 (0 to 73)

6 (1 to 31)

>11.14

14,78

25

78 (32 to 158)

10 (0 to 89)

6 (1 to 44)


Caffeine intake (food frequency questionnaire data) according to maternal characteristics, n = 59,123, in the Norwegian Mother and Child Cohort Study 2002 to 2009.

aP value for being sampled from the same distribution (Kruskal-Wallis test).

cMarital status was defined as either married/cohabiting or not.

BMI = body mass index.

Sengpiel et al. BMC Medicine 2013 11:42   doi:10.1186/1741-7015-11-42

Open Data