Women who drink too much coffee in pregnancy are more likely to have overweight children, a new study has shown.
Youngsters whose mothers drank the equivalent of more than three cups of coffee a day were found to be more than 1lb heavier than children of women consumed little or no caffeine by the age of eight.
Current NHS advice suggests women should drink no more than 200mg of caffeine per day, the equivalent of two cups. But the Norwegian researchers said ‘complete avoidance’ could be safer.
Caffeine passes rapidly through tissues, including the placenta, and takes the body longer to get rid of during pregnancy. It has been linked to a heightened risk of miscarriage and restricted fetal growth.
The researchers say there is a plausible biological explanation which could account for the excess weight gain. They believe caffeine may change ‘fetal programming’ and modify the overall weight trajectory of the child.
“The results add supporting evidence for the current advice to reduce caffeine intake during pregnancy and indicate that complete avoidance might actually be advisable,” said Dr Eleni Papadopoulou.
During the study women mums-to-be were asked to quantify their food and drink intake from among 255 items, including caffeine, using a specially adapted Food Frequency Questionnaire.
Daily intake was grouped into: 0-49 mg (low); 50-199 mg (average); 200-299 mg (high); and 300 + mg (very high).
Average, high, and very high caffeine intake during pregnancy were associated with a heightened risk of faster excess growth during their child’s infancy than low intake, after taking account of potentially influential factors.
And exposure to any caffeine level while in the womb was associated with a heightened risk of overweight at the ages of 3 and 5 years, although this persisted only for those 8 year olds whose mums had had a very high caffeine intake during their pregnancy.
Children exposed to very high levels of caffeine before birth weighed 67-83 g more in infancy (3-12 months); 110-136 g more as toddlers; 213-320 g more as pre-schoolers (3-5 years); and 480g more at the age of 8 than children who had been exposed to low levels.
The research was published in the journal BMJ Open.