A: The good news is that a limited amount of caffeine is unlikely to cause any harm.

Caffeine is not without controversy, however. Some studies show an association between moderate coffee intake and first trimester miscarriage, but it's been hard to sort out whether caffeine is the culprit. Women who are very nauseous during early pregnancy often avoid coffee. These women may be nauseous because of higher hormone levels and may be less likely to miscarry. Women with lower hormone levels are less likely to be nauseous and more likely to continue drinking coffee. If these coffee drinkers miscarry, it may well be a result of having lower hormone levels rather than a result of the caffeine exposure.

Studies do suggest that high levels of caffeine are indeed associated with an increased risk of miscarriage, so it is wise to avoid high caffeine intake. Other reasons to limit your caffeine consumption:

• Caffeine is a diuretic, causing you to urinate more during pregnancy, which may increase your chance of dehydration.
• Coffee and tea contain phenols, compounds that interfere with the absorption of iron. Most pregnant women are anemic and benefit from extra iron rather than less.
• Caffeine intake during pregnancy can slightly raise the risk of preterm delivery and delivering a baby of lower birth weight.
• Caffeine is a stimulant that raises your blood pressure and heart rate. It can also cause nervousness, headaches and interfere with your sleep – a precious commodity during pregnancy.

If you would like to continue drinking caffeinated beverages, use common sense. Keep your intake below 300 milligrams a day, and avoid caffeine in the afternoons and evenings.

Here's a list of the milligrams of caffeine in common beverages. Be aware that drinking strong coffee and using a large mug will increase the amount of caffeine in a serving.