To the Editor.
—The reassuring conclusions of the recent, much publicized article1 on caffeine consumption and fetal growth appear to be misleading. While the ascertainment of caffeine consumption at multiple times during pregnancy was a great strength of the study, the results were based on only 352 live births in a select population of women who volunteered for the study, and therefore may not have been representative of the general population of pregnant women, as was noted by the authors. The population was highly educated (70% had at least a bachelor's degree and 41% had at least some graduate school) and only 10% were smokers. More importantly, the amount of caffeine consumed by this population was very low; 62% consumed less than 100 mg/d on average throughout pregnancy. No previous study has found effects of caffeine on fetal growth at these low levels; however, 10 of 13 studies have
Hatch EE, Bracken MB. Caffeine Use During Pregnancy: How Much Is Safe?. JAMA. 1993;270(1):46-47. doi:10.1001/jama.1993.03510010052024