aternal caffeine consumption during pregnancy nd the risk of miscarriage: a prospective cohort study

affeine, 1,3,7-trimethylxanthine, is among the most frequently inested pharmacologically active subtances in the world. 1 Caffeine can eadily cross the placental barrier to the etus; its clearance is prolonged in pregant women, and its metabolism rate is ow in the fetus because of low levels of nzymes. It may also influence cell deelopment through increasing cellular yclic adenosine monophosphate concentrations and decrease intervillous placental blood flow via increasing circulating catecholamines. Therefore, caffeine could have an adverse effect on fetal development. Indeed, caffeine intake has been reported to increase the risk of miscarriage. Although numerous studies on maternal caffeine consumption and the risk of miscarriage have been published since the 1980s, the effect of caffeine intake on the risk of miscarriage remains controversial because of methodological limitations in past studies. 10 Many studies have relied on retrospective information, which is subject to recall bias. 8,11,12