A new study provides evidence that a pregnant woman can consume moderate amounts of caffeine without impairing her baby's development, ReutersHealth reports this week. The findings add to a conflicting body of research into the effects of caffeine on the developing fetus. While some studies suggest that caffeine may increase the risk of having a low birth weight baby, preterm delivery, fetal growth retardation and miscarriage, other research has failed to confirm these associations. Studies on animals led to a 1980 recommendation by the US Food and Drug Administration (FDA) that pregnant women avoid caffeine altogether. But, according to Dr. John Larsen, of George Washington University in Washington, DC, the new study supports a "common-sense approach" to caffeine. "I tell women, 'You can certainly have your cup of coffee in the morning,'" he said in an interview with Reuters Health. "There is no evidence of a real harmful effect." In the study, Dr. Laura M. Grosso and colleagues from Yale University School of Medicine in New Haven, Connecticut, followed more than 2,700 women, interviewing them about their intake of coffee, tea and soft drinks during the first and third trimesters of pregnancy. Information about smoking, alcohol, drug use and medical history was also obtained. The findings, published in a recent issue of the journal Epidemiology, show that women in general consumed more caffeine during the first month than during the seventh month of pregnancy. During the first month of pregnancy, 38 per cent of women reported drinking coffee, which was the largest source of caffeine consumption. In the seventh month of pregnancy, coffee remained the primary source of caffeine, with 35 per cent of women drinking at least a cup per week and 21 per cent drinking one or two cups a day. But average caffeine consumption had dropped to 54 mg per day. The researchers found no association between caffeine consumption and intrauterine growth retardation, or low birth weight. "This study provides evidence that antenatal caffeine consumption has no adverse effect on foetal growth," Grosso and her colleagues conclude. The investigators note that their study has several limitations, including the fact that the proportion of women who consumed more than 300 mg of caffeine daily - about three cups of coffee - was small at both 1 month (5%) and 7 months (2%). They add that it is difficult to measure caffeine exposure accurately. "There is much biological evidence to support a possible adverse effect of [prenatal] caffeine consumption on fetal growth," the authors note.