A new study has found that regular use of cell phones during pregnancy is likely to cause behavioural problems in the offspring. However this risk can augment to higher levels if the offspring begins to use mobiles themselves by the time they are seven.

The researchers at the University of California and the University of Southern California are said to have made these observations.

They found out that the children who had been exposed to mobile phones in the womb and had also started using them in early childhood had 50% more chances to have behavioural problems aged seven in comparison to youngsters who were exposed to neither.

The Daily Telegraph reported that the youngsters who were exposed to phones in childhood and not in the womb had 20% more chances to display abnormal behaviour whereas the ones exposed to mobile phones while in womb only were associated to a 30% increase.

Dr. Andrew Adesman, chief of developmental and behavioural pediatrics at the Steven and Alexandra Cohen Children's Medical Center of New York in New Hyde Park said, "The study's methodology was rigorous and responsible. The researchers took into account as many possible variables as they could, given the limitations of the data set”.