A new study published online in The FASEB Journal shows that the equivalent of one dose of caffeine (just two cups of coffee) ingested during pregnancy may be enough to affect fetal heart development and then reduce heart function over the entire lifespan of the child. In addition, the researchers also found that this relatively minimal amount of exposure may lead to higher body fat among males, when compared to those who were not exposed to caffeine. Although the study was in mice, the biological cause and effect described in the research paper is plausible in humans.

The headline of this post says it all. However, a closer look at this study shows that it was conducted on mice for a very short period of time, using injectable caffeine. That’s a far cry from one cup of green tea per day, which is about the maximum amount we believe is safe during pregnancy. The research for this is in our chapter on recommended foods. It’s best to avoid caffeine as much as possible – we did for our own children – but Lana did occasionally have some green tea.

As you’ll read in the book, one of the most important things you can do while you are pregnant is to relax. No pregnant woman eats a perfect diet, and despite the alarmist articles you’ll read, very small amounts of caffeine on occasion are very unlikely to hurt a fetus. The stress you might feel from trying to be perfect can be more harmful than minor ones like green tea.

Coffee, on the other hand, is off the list while you’re pregnant. Have a sip of someone else’s if you like, but don’t make the mistake of going for decaf. Decaf is almost always contaminated with levels of mold toxins unsafe for fetuses because it’s the caffeine that stops mold from growing naturally, and decaf processing is often chemical-based.

But if you have a little tea on occasion, relax – you and your baby will be just fine.