Is caffeine safe during pregnancy?

Pregnancy greatly reduces our ability to metabolize caffeine.

For example, in a typical adult, caffeine blood levels fall by about half, also known as

the half-life in five hours. As you reach mid-pregnancy, that time

doubles, and by the time you reach the third trimester, it can take 15 hours or more to

reduce caffeine to a similar level. At the same time, fatigue is one of the most common

complaints of pregnant women. Couldn't a little extra energy boost from slowly

metabolizing caffeine be a good thing? Unfortunately, caffeine readily passes through the placenta,

and if you think expecting moms metabolize slowly, babies have even less capacity to metabolize

caffeine with a half-life of 80 hours. That's more than three days. But to what effect?

In pregnancy, is caffeine a friend or foe? Respected authorities, including the World Health

Organization, the European Food Safety Authority, and the American College of Obstectrics and

Gynecology, have guidelines for a positive pregnancy experience,

including restricting caffeine intake to reduce the risk of pregnancy loss and low birth weights.

Higher caffeine intake pre-pregnancy is associated with higher risk of miscarriages, and higher

intake during pregnancy is associated with low birth weight.

So the World Health Organization suggests reducing consumption to less than 300 milligrams of caffeine a day.

Whereas the European Food Safety Authority suggests 200 milligrams per day may be the safety limit,

an agreement with the American College of Obstetrics and Gynecology.

That comes out to about two cups of brewed coffee a day, assuming that's your sole caffeine

source. Since those guidelines were issued, this study of 2,000 moms found that even just a half

cup of coffee or so a day was associated with a lower birth weight by about

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