Struggling to get your baby to sleep? Cut down your coffee consumption, for researchers say that breastfeeding mothers can pass on the caffeine in coffee through their milk.

A team at Rochester University in New York says that drinking coffee, tea and soft drinks and even eating chocolate increases the level of the stimulant in the blood. Babies can become restless, awake and irritable, when it is passed on through a mother's milk.

Team leader Dr Ruth Lawrence, also the editor of the 'Breastfeeding Medicine' journal, said that babies have difficulties in breaking down and removing caffeine from their bodies especially in their first two weeks of life. This can lead it to accumulate causing adverse symptoms.

"Usually a mother, particularly if she is breastfeeding, is cautioned to limit her caffeine intake," the 'Daily Mail' quoted her as telling the 'Journal of Caffeine Research'.
She said mothers should "try to void the excesses that might really add up to a lot of caffeine".

But how many cups of coffee constitutes an "excessive amount"? According to Dr Lawrence, it depends on individual mother.

However, Dr Lawrence said: "Unfortunately a lot of things about breastfeeding are based on opinion, and I do not know that the 'safe' amount of caffeine for daily use has been carefully measured.

"We had a case here in which a child was brought in, thought to be having seizures and was headed for the million- dollar workup, the EEG, the MRI, the works.

"In the emergency room we drew a caffeine level. It was off the charts! Taking a history from the mother, she said 'oh year, I drink coffee all the time. I have a cup ready for me all day long. Is that a problem?"

Dr Lawrence said they learned about the dangers of caffeine and newborns after using it to stimulate breathing in babies in neonatal intensive care.

"We discovered that we overdosed them very quickly. Now they are only dosed once a day in order to keep their levels under control because the metabolism is so poor," she said.

She added: "Some individuals are more sensitive than others. It would be a good starting point if a child is very restless, that one might consider reducing the intake of caffeine."