Brewed coffee and espresso both contain caffeine, which is a natural stimulant. Coffee is usually served by the cup, while espresso is served by the shot, although serving sizes can vary. Brewed coffee takes longer to make than espresso, which is typically thicker and stronger than brewed coffee.
One 8-ounce cup of coffee has 95 milligrams of caffeine and a 1-ounce single shot of espresso has 64 milligrams. Consuming too much caffeine can make you restless, anxious and irritable. It can also interact with certain medications. Pregnant women may need to cut back on caffeine consumption. While moderate caffeine consumption doesn't appear to cause miscarriage or preterm birth, according to The American College of Obstetricians and Gynecologists, it's still unclear whether high levels of caffeine consumption have any link to miscarriage, according to an article published in the August 2010 issue of "Obstetrics & Gynecology." Speak with your healthcare provider if you want to know if caffeine is safe for you.