2635 healthy pregnant woman was accompanied from the first pregnancy third up to the birth. In this time its Caffeine consumption (coffee, tea, Cola, cocoa) was observed and regularly the saliva was analyzed at the same time, in order to measure, how and how quickly the Caffeine is taken up from the body and reduced again. The pregnant women on the average took 159 milligrams Caffeine daily to itself, thus usually clearly less than the harmless quantity accepted so far.

When the children came to the world, was it shown: The more Caffeine, was the smaller the birth weight of the baby had taken a pregnant woman to itself. Thus the babies of women, who had consumed at least 200 milligrams Caffeine daily (two cups coffee), with a birth weight smaller around 60 to 70 gram came to the world than the children of becoming mothers, who had drunk coffee only up to a cup.

This decrease of the birth weight has on healthy babies, who are born around the calculated date, no negative effects, explains the scientists of the university of Leicester. With a Prematurity or a baby with anyway small birth weight however quite represent this weight reduction a further risk. They recommend from there women, who wish itself a baby to already reduce or adjust even completely from the time of fertilization at the Caffeine consumption from all sources to a minimum.