Coffee is consumed in large quantities worldwide and any adverse effects would likely have important public health consequences. Because of the widespread exposure to coffee and other caffeine-containing beverages and because teratogenic effects of caffeine have been recorded in several species since 1960, women are concerned that there may be reason to limit their intake of coffee when pregnant. Several human studies on birth defects have been conducted and the overall results do not implicate coffee as a likely human teratogen. However, there is some evidence that consumption of three or more cups of coffee per day may have a modest effect on lowering infant birth weight. Studies of coffee consumption and increased rates of spontaneous abortion and delayed time to conception are inconsistent and conclusions cannot yet be drawn.