Caffeine in Pregnancy: How Much is Safe?

Recently, a worried mother-to-be asked me whether she should be concerned about the amount of tea she was drinking. She enjoyed a good cup of black tea, but wondered if the caffeine would harm her baby. This article strives to answer that question.

Currently, Health Canada recommends that women of childbearing age consume no more than 300 mg of caffeine a day, which works out to about three 8oz cups of coffee. The following chart illustrates the caffeine content of some common foods and beverages:

There have been a number of studies investigating the effects of caffeine on pregnancy outcomes. Two issues in particular have made media headlines this year. One is the finding that caffeine doubles the risk of miscarriage, and the other that caffeine is linked to low infant birth weight. While alarming at first glance, a closer look reveals two important points. First, the amount of caffeine found to be problematic was in excess of 200 mg per day, or two 8 oz cups or regular coffee. And secondly, the studies only demonstrated an association between heavy caffeine consumption and miscarriage and low birth weight, not causation. In the case of caffeine and low birth weight, other studies have not shown any link at all.

So what to make of all this? As recent research suggests an increased risk of miscarriage or low birth weight infants with increasing caffeine intake, it seems prudent that caffeine intake be limited to 200 mg or less per day during pregnancy. That's two small cups of regular coffee. A caveat here is to realize the size of the beverage, as a large or extra large coffee is more like three cups. Another safe choice is to choose decaffeinated tea, coffee or soft drinks. These provide a mere fraction of the caffeine content with no loss of taste.

There is still much debate in the research community over the safety of caffeine during pregnancy. We know that there is definitely no harm in avoiding it all together, but most experts agree that a little caffeine is not a problem, keeping in mind the 200 mg per day limit that research suggests as the "safe" cutoff. So enjoy your (8 oz!!) morning cup of coffee or tea with peace of mind. Like most things in life, the key to health is moderation.