Women who drink just two cups of coffee a day while pregnant risk their children being overweight, a study has found.
Babies exposed to moderate or high levels of caffeine in the womb have a higher chance of being overweight in early childhood, the research says.
The findings call into question NHS guidelines which say expectant mothers can safely consume up to two cups of coffee a day.
Researchers looked at the link between caffeine intake during pregnancy and the weights of children up to the age of eight.
Studying 51,000 mother and infant pairs in Norway between 2002 and 2008, they measured the expectant mothers’ daily intake of caffeine – found in chocolate, tea and many soft drinks as well as coffee – at 22 weeks of pregnancy.
More than four in ten were classed as having an average caffeine intake, consuming the equivalent of up to two cups of coffee a day, while 7 per cent were classed as high intake (up to three cups) and 3 per cent were considered to have a ‘very high’ intake (three or more cups). Just under half of the mothers-to-be were classified as low caffeine intake, consuming the equivalent of half a cup of coffee.
Their children’s weight and height were then measured at six weeks old, at three, six, eight, 12 and 18 months old, and then at two years and every year up to age eight. Those whose mothers had been classed as average caffeine consumers were 15 per cent more likely to be heavier – but not taller – than those whose mothers avoided caffeine, the researchers found. This correlation grew to 30 per cent among the children of high caffeine consumers, and 66 per cent among the children of very high consumers, according to the study in medical journal BMJ Open.
Children of very high caffeine consumers weighed up to three ounces more between three and 12 months, rising to a pound more at age eight.
But Professor Jean Golding, of the University of Bristol, said: ‘It will be important to determine whether any effects of high maternal caffeine intake are apparent at later ages, or … confined to the pre-puberty ages.’
How a tipple can make PMS worse
The cramps, mood swings and bloating are enough to make any woman reach for a glass of wine. But if you have ever been tempted to soothe premenstrual syndrome (PMS) with a tipple, you may want to think again.
Drinking even moderate amounts of alcohol has been linked to an increased risk of getting symptoms.
At least one in five cases of PMS in Europe could be the result of alcohol intake, which researchers believe could alter hormone levels during the monthly cycle. It is known female hormone oestrogen has an effect on pain levels. British and Spanish researchers found women who regularly consumed one unit a day – less than a 175ml glass of wine – were nearly 50 per cent more likely to suffer symptoms than those who do not drink at all. This rose to 79 per cent in those who drank a couple of small glasses a day.
Professor Hazel Inskip, of the University of Southampton, said: ‘If you have PMS, it might be worth cutting down the alcohol to see if it has an effect.’ The study, published in BMJ Open, examined data from 19 studies involving 47,000 participants.