Regular use of mobile phones in pregnancy may be linked to behavioural problems in children, new research suggests.
The risk is even higher if children start using mobile phones themselves by the time they are seven, according to the study of almost 29,000 youngsters.
The findings, from a team including experts from the University of California Los Angeles and the University of Southern California, were published in the Journal of Epidemiology and Community Health.
They show that children who were exposed to mobile phones in the womb and then in early childhood were 50 per cent more likely to have behavioural problems aged seven than youngsters exposed to neither.
Only being exposed to mobile phones while in the womb was linked to a 30 per cent increase, while youngsters who were exposed to phones in childhood but not in the womb were 20 per cent more likely to display abnormal behaviour.
It is the second study by the same team to find such an association. The first involved a separate group of almost 13,000 children.
The studies relied on mothers scoring their own child's behaviour and recalling their own mobile phone use.
When the results from both studies were combined, more than 10 per cent of children exposed to mobile phones in pregnancy had mothers who spoke on them at least four times a day, while half of women had their phone turned on at all times.
The authors concluded: 'Although it is premature to interpret these results as causal, we are concerned that early exposure to cell phones could carry a risk, which, if real, would be of public health concern given the widespread use of this technology.'
But many experts, including Professor David Spiegelhalter, from the University of Cambridge, are sceptical of the results.
Speaking in the Daily Telegraph, he said: 'One finding is that very young children who use mobile phones show more behavioural disorders: this may well be the case, but is it plausible that the first causes the second?
'The authors say that "early exposure to cell phones could carry a risk which, if real, would be of public health concern". Well, I might just as well say 'Paul's (the octopus that 'predicted' World Cup results) psychic abilities, if real, would revolutionise our thinking about molluscs.'
And Professor Patricia McKinney, Emeritus Professor of Paediatric Epidemiology at the University of Leeds, said: 'There is no scientific basis for investigating exposure of the growing baby when pregnant mothers use a mobile phone, as exposure to radiofrequency radiation from mobile phones is highly localised to the part of the head closest to the phone; there is no evidence to suggest that other parts of the body, such as the abdomen where the baby is growing, are affected by mobile phone use.
'We also have no evidence that a pregnant mother's behaviour is related to her mobile phone use and thereby affecting her baby. The risks linked to prenatal exposure are therefore questionable.'
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