If you experience these symptoms, see your doctor and try going off caffeine to see if that brings relief. In 1980, the FDA issued a recommendation that pregnant women try to eliminate caffeine. That was based largely on a study in which very large doses of caffeine were administered to pregnant lab rats. While the FDA still suggests cutting back on caffeine, many researchers today feel that the results of those experiments can't be applied to humans. A review of more than 20 studies conducted since 1980 found no link between moderate caffeine consumption and adverse outcomes in pregnancies.
Caffeine can pass through the placenta and into the breast milk.
According to the International Food Information Council Foundation, a pregnant or nursing mother can safely consume a moderate amount of caffeine without passing on a significant quantity to the baby. A 1990 study by the Centers for Disease Control and Prevention and Harvard University concluded that moderate caffeine consumption had little or no effect on fertility or on the amount of time it takes women to conceive. If there is a connection, it's not well understood. It could be, say experts, that because PMS causes fatigue, some women drink more coffee as self-medication. A recent study found that coffee drinkers have a lower chance of developing Parkinson's than nondrinkers, but don't assume that there's a direct link.