There was a direct relationship between caffeine consumption and the risk of spontaneous abortion early in pregnancy, they say. However, reducing caffeine intake during early pregnancy may be prudent. The study found that women who drank more than four cups per day doubled their risk of miscarriage. The Swedish results are in rough agreement with the findings of an American report published just over a year ago in the same journal, says Dr. Mark Klebanoff, director of the division of epidemiology, statistics and prevention research at the National Institute of Child Health and Human Development, who led the earlier study. A pregnant woman can safely drink up to four cups of coffee or six cans of soda a day without increasing the risk of miscarriage, they said.
Moderation is the way to go.
One complicating factor is that it is hard to determine whether high caffeine consumption is a cause or an effect of early miscarriage, Klebanoff says. In some of these miscarriages, when you do a sonogram, you find that the fetus has been dead for several weeks. But moderation is always good advice. That recommendation, based primarily on animal studies, has not changed. A woman who is pregnant or plans to become pregnant is wise to limit her intake of coffee to less than five cups a day and of caffeinated sodas to less than six cans a day.