Verena Sengpiel, Elisabeth Elind, Jonas Bacelis, Staffan Nilsson, Jakob Grove, Ronny Myhre, Margaretha Haugen, Helle M Meltzer, Jan Alexander, Bo Jacobsson and Anne-Lise Brantsaeter
BMC Medicine 2013, 11:42 doi:10.1186/1741-7015-11-42
Published: 19 February 2013
Published: 19 February 2013
Abstract (provisional)
Background
Pregnant women consume caffeine daily. The aim of this study was to examine the association
between maternal caffeine intake from different sources and (a) gestational length,
particularly the risk for spontaneous preterm delivery (PTD), and (b) birth weight
(BW) and the baby being small for gestational age (SGA).
Methods
This study is based on the Norwegian Mother and Child Cohort Study conducted by the
Norwegian Institute of Public Health. A total of 59,123 women with uncomplicated pregnancies
giving birth to a live singleton were identified. Caffeine intake from different sources
was self-reported at gestational weeks 17, 22 and 30. Spontaneous PTD was defined
as spontaneous onset of delivery between 22+0 and 36+6 weeks (n = 1,451). As there
is no consensus, SGA was defined according to ultrasound-based (Marsal, n = 856),
population-based (Skjaerven, n = 4,503) and customized (Gardosi, n = 4,733) growth
curves.
Results
The main caffeine source was coffee, but tea and chocolate were the main sources in
women with low caffeine intake. Median pre-pregnancy caffeine intake was 126 mg/day
(IQR 40 to 254), 44 mg/day (13 to 104) at gestational week 17 and 62 mg/day (21 to
130) at gestational week 30. Coffee caffeine, but not caffeine from other sources,
was associated with prolonged gestation (8 h/100 mg/day, P <10-7). Neither total nor
coffee caffeine was associated with spontaneous PTD risk. Caffeine intake from different
sources, measured repeatedly during pregnancy, was associated with lower BW (Marsal
-28 g, Skjaerven -25 g, Gardosi -21 g per 100 mg/day additional total caffeine for
a baby with expected BW 3,600 g, P <10-25). Caffeine intake of 200 to 300 mg/day increased
the odds for SGA (OR Marsal 1.62, Skjaerven 1.44, Gardosi 1.27, P <0.05), compared
to 0 to 50 mg/day.
Conclusions
Coffee, but not caffeine, consumption was associated with marginally increased gestational
length but not with spontaneous PTD risk. Caffeine intake was consistently associated
with decreased BW and increased odds of SGA. The association was strengthened by concordant
results for caffeine sources, time of survey and different SGA definitions. This might
have clinical implications as even caffeine consumption below the recommended maximum
(200 mg/day in the Nordic countries and USA, 300 mg/day according to the World Health
Organization (WHO)) was associated with increased risk for SGA.
