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Table 8 Birth weight and maternal caffeine intake at different timepoints before and during pregnancy

From: Maternal caffeine intake during pregnancy is associated with birth weight but not with gestational length: results from a large prospective observational cohort study

Modela

Caffeine source

Birth weight (Marsal)

Birth weight (Skjaerven)

Birth weight (Gardosi)

  

β (g) 95% CI

Pvalue

β (g) 95% CI

Pvalue

β (g) 95% CI

Pvalue

Pre-pregnancy:

I

Total

-3

-5 to-2

<10-6

-2

-4 to-1

<10-3

-1

-3 to 0

0.04

 

Coffee, all types

-3

-4 to-2

<10-4

-2

-3 to 0

0.02

-1

-3 to 0

0.07

 

Caffeinated soft drinksb

-3

-7 to 1

0.1

-4

-8 to 0

0.06

-1

-5 to 3

0.6

 

Black tea

-16

-23 to-9

<10-5

-16

-23 to-8

<10-4

-6

-13 to 1

0.1

II

Total

1

-1 to 3

0.3

2

0 to 3

0.03

2

1 to 4

0.003

 

Coffee, all types

1

-1 to 3

0.2

2

0 to 4

0.02

3

1 to 4

<3 × 10-3

 

Caffeinated soft drinksb

4

-3 to 10

0.3

3

-3 to 10

0.3

5

-1 to 11

0.1

 

Black tea

-12

-21 to-2

0.02

-13

-22 to-3

0.01

-3

-12 to 7

0.6

17th week of gestation:

I

Total

-9

-12 to-7

<10-17

-8

-10 to-6

<10-13

-7

-9 to-5

<10-10

 

Coffee, all types

-9

-11 to-6

<10-11

-7

-10 to-5

<10-7

-7

-10 to-5

<10-8

 

Caffeinated soft drinksb

-9

-15 to-4

<2 × 10-3

-10

-15 to-4

<10-3

-6

-11 to-1

0.03

 

Black tea

-14

-22 to-6

<10-3

-12

-20 to-4

<5 × 10-3

-6

-14 to 2

0.13

II

Total

-8

-11 to-6

<10-8

-8

-10 to-5

<10-8

-7

-10 to-5

<10-8

 

Coffee, all types

-8

-11 to-4

<10-5

-8

-11 to-4

<10-5

-7

-10 to-4

<10-4

 

Caffeinated soft drinksb

-13

-22 to-5

<3 × 10-3

-13

-22 to-4

<4 × 10-3

-12

-20 to-3

<7 × 10-3

 

Black tea

-1

-12 to 9

0.8

2

-9 to 13

0.8

-3

-14 to 7

0.5

30th week of gestation:

I

Total

-8

-10 to-6

<10-13

-7

-9 to-5

<10-10

-6

-8 to-4

<10-7

 

Coffee, all types

-9

-11 to-6

<10-10

-7

-9 to-4

<10-7

-7

-10 to-5

<10-8

 

Caffeinated soft drinksb

-2

-6 to 3

0.5

-3

-7 to 2

0.3

0

-5 to 4

0.9

 

Black tea

-18

-27 to-10

<10-4

-18

-27 to-9

<10-4

-8

-16 to 1

0.08

II

Total

-5

-7 to-3

<10-4

-5

-7 to-3

<10-4

-4

-7 to-2

<10-3

 

Coffee, all types

-6

-9 to-3

<10-3

-5

-9 to-2

<2 × 10-3

-6

-9 to-3

<10-4

 

Caffeinated soft drinksb

-1

-6 to 5

0.8

-1

-6 to 4

0.7

0

-5 to 5

0.9

 

Black tea

-14

-24 to-4

<5 × 10-3

-15

-25 to-5

<3 × 10-3

-6

-16 to 3

0.2

  1. Birth weight (BW) and maternal caffeine intake reported at different timepoints before and during pregnancy (data from Q1 and Q3), linear regression for three caffeine sources as well as total caffeine intake, n = 59,123 in the Norwegian Mother and Child Cohort Study, 2002 to 2009. β = BW gain (in g) per 100 mg additional caffeine/day for a baby with an expected BW of 3,600 g.
  2. a P value, linear regression adjusted as follows. Model I: maternal age, pre-pregnancy body mass index, parity, history of preterm delivery, baby's sex, nausea during second trimester, smoking habits, passive smoking, nicotine intake from other sources, alcohol consumption during pregnancy, energy intake, maternal education, marital status, household income. In the analysis of the separate caffeine sources, these were mutually adjusted (coffee, caffeinated soft drinks, black tea and chocolate). Model II: as model I, as well as for caffeine intake from different sources as reported at the other studied timepoints.
  3. bCaffeinated soft drinks included in Q1 and Q3: Coca Cola/Pepsi with sugar, Coca Cola light, Pepsi Light.