Drink Up—or Decaf? New Findings on Coffee During Pregnancy

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When it comes to the "Is it safe?" list of pregnancy dos and dont's, there's a lot of conflicting information as to where exactly coffee—and caffeinated drinks in general—fits in.

According to the World Health Organization, pregnant women should limit themselves to 300 milligrams of caffeine a day—the equivalent to about three eight-ounce cups of regular brewed coffee. The American College of Obstetricians and Gynecologists, however, recommends moms-to-be consume no more than 200 milligrams a day—two cups. And to add to the confusion, many doctors and midwives still says it's best to simply drink decaf.

Which, of course, leaves hordes of latte-loving moms-to-be wondering, who's right? To answer this question, researchers in Sweden and Norway looked at caffeine consumption in almost 60,000 pregnancies—and the results are buzz-worthy.

For example, moms who got a daily dose of between 200 and 300 milligrams of caffeine were up to 62 percent more likely to have a small for gestational age baby compared to moms whose caffeine intake from all sources (including foods like chocolate) was less than 50 mg daily.

Researchers were even able to pinpoint exact amounts of weight. For every 100 mg of average daily caffeine intake throughout pregnancy, the result was a loss in birth weight of up to one ounce—a two cup a day habit might shave up to two ounces of babies' birth weights, and so on. It might not seem like much for babies predicted to weigh eight pounds at birth, but for smaller babies, especially those born preterm, every ounce can matter.

And speaking of preterm birth, the study did not find a link between caffeine intake and delivering early (though other studies have). In fact, women with higher caffeine intakes actually increased the length of pregnancy by about five hours, on average, over women whose caffeine intakes were minimal. All by itself, drinking just 100 milligrams a day coffee was found to add eight hours to pregnancy! Why? It remains a mystery.

Does this mean it's time to downgrade caffeine intake to under 100 mg daily—or better yet, under 50 mg? According to one study author, Dr. Verena Sengpiel of the Sahlgrenska University Hospital in Sweden, "recommendations might have to be re-evaluated," though WHO, ACOG, and other groups have yet to respond.

Given all the recent research about caffeine's safety during pregnancy, Rob van Dam, an assistant professor in the department of nutrition, Harvard School of Public Health, thinks it may be best to say the "jury is still out" on this one. "We know that the caffeine goes through the placenta and reaches the fetus, and that the fetus is very sensitive to caffeine; it metabolizes it very slowly. So for pregnant women it seems prudent to reduce coffee consumption to a low level, for example one cup a day," he writes in a Q&A about caffeine and pregnancy.

Of course, the best way to find out what level of caffeine consumption is safest for you during pregnancy is to bring this topic up with your own doctor or midwife. But for Colorado mom Heather Simpson, the choice to give up caffeine was easy... because her baby wasn't having any of it.

"My mornings always started with a venti Starbucks, but then morning sickness hit and this baby made it clear, 'No coffee for me!' Coffee, cola, chocolate, tea... it all made me gag, so it all went," she remembers. "My doctor's advice was to cut down to a cup of regular coffee a day, but even that was a no-go. By the time morning sickness ended, I had completely gotten over caffeine withdrawal and I just decided to stick with it."

Her baby is now nine months old, and Simpson is still caffeine-free.

"I will thank her later for helping me kick my coffee habit!"