Is it dangerous to get more than a moderate amount of caffeine during pregnancy?
No one knows for sure. Some studies found that women who got 300 mg of caffeine or more a day had a higher risk of miscarriage. And according to the march of dimes, high caffeine consumption may slightly increase the risk of preterm labor or low birth weight, which could make a difference for a baby who's already at risk for these problems. Other research has shown that babies of women who got more than 500 mg a day had faster heart rates and breathing rates, and spent more time awake in the first few days after birth. Though the research isn't conclusive, it makes sense to cut back if you're downing more than three cups of java or more than 300 mg a day from all sources — sodas, tea, coffee, and chocolate — combined.
One thing's for sure: you'll feel better if you cut back on caffeine. It's a stimulant, so it increases your heart rate and metabolism and can cause insomnia, nervousness, and headaches. It contributes to heartburn by stimulating the secretion of stomach acid. It's a diuretic, so it makes you pee more often and become dehydrated more easily. What's more, it has no nutritional value — in fact, it causes your bones to lose calcium. And all these effects are only likely to get worse as you approach your due date because your body breaks down caffeine more slowly as your pregnancy progresses, and that means a higher level of caffeine in your bloodstream (and in your baby's).
By the way, there's one more reason to cut back on coffee and tea during your pregnancy, whether it's caffeinated or not. These beverages contain compounds called phenols that make it harder for your body to absorb iron. This is particularly important because many pregnant women are already low on iron. If you drink any coffee or tea, have it between meals so it has less of an effect on your iron absorption.
