Caffeine (1, 3, 7-trimethylxanthine) is a methylxanthine that easily crosses the placental barrier, substantial amounts passing into the amniotic fluid, umbilical cord blood, and the plasma and urine of the neonates. The main sources of caffeine are coffee, tea, chocolate and cola soft drinks. Moreover, about 1000 prescribed drugs and 2000 non-prescribed drugs contain caffeine, and 25 of these drugs can be used during pregnancy. Although animal studies indicate that caffeine leads to a decrease in fetal intrauterine growth, low birth weight, fetal re-absorption and teratogenesis, these findings are still inconclusive in the epidemiological studies. Since foods containing caffeine are widely consumed during pregnancy, it is important to evaluate if the consumption of this substance is associated with a reduction in gestational age. This article examines current knowledge on caffeine intake during pregnancy, based on epidemiological studies evaluating the association between caffeine intake and prematurity, the sources of caffeine and its consumption during pregnancy, the biochemistry, physiopathology and biological plausibility of the association, and the main limitations of the studies on caffeine and prematurity.
caffeine intake; pregnancy; prematurity