Jack James, a professor in the psychology department at Reykjavik University in Iceland, analyzed findings from almost 40 studies looking at caffeine consumption during pregnancy. He found that most of the studies showed a correlation between caffeine intake and birth problems or health concerns for the baby, including miscarriage, stillbirth, low birth weight, childhood leukemia, and having a child that is overweight or obese. These risks increased the more caffeine was consumed, according to the analysis published in the peer-reviewed journal BMJ Evidence-Based Medicine.
In conclusion, James said pregnant women and those trying to conceive should avoid caffeine altogether.
“Current health recommendations concerning caffeine consumption during pregnancy are in need of radical revision,” he wrote. “Specifically, the cumulative scientific evidence supports pregnant women and women contemplating pregnancy being advised to avoid caffeine.”
But several experts not affiliated with the analysis criticize that conclusion. They advise pregnant women to stick with established recommendations to limit caffeine and not feel as if they have to completely remove it from their diet.
“People should not be panicked by this information. They should not feel guilty, like ‘I am four weeks pregnant and I had coffee,'” Dr. Stacy Beck, an assistant professor at the University of Pittsburgh, told Today.
The American College of Obstetricians and Gynecologists (ACOG) advises pregnant women to limit their caffeine intake to 200 milligrams a day. That’s about one 11-ounce cup of coffee. Caffeine is also found in smaller concentrations in energy drinks, some sodas, chocolate, and tea.
Here are some of the reasons Beck and other experts say James’s conclusion is overblown.
- There are no new findings. The analysis was looking at old studies. Those studies contain the same kind of data that has informed ACOG’s recommendation to limit – but not necessarily avoid – caffeine while pregnant.
- Most of the studies are observational. It would be unethical to perform a trial in which some pregnant women are given vast amounts of caffeine and others are not. For that reason, the studies analyzed mostly involved asking women to recall how much caffeine they had during pregnancy. But because it can be hard to remember exactly what one eats and drinks every day, these recollections may not be accurate.
- It doesn’t prove caffeine causes problems. Beck and another expert interviewed by Today, Emily Oster, pointed out that women who consume higher amounts of caffeine may also tend to drink and smoke more, two factors that are proven to negatively affect birth outcomes.
- The interpretation of the data may be faulty. Australian epidemiologist Gideon Meyerowitz-Katz questioned the calculations in the analysis and said the risk estimates are incorrect. He likened the analysis to an academic version of an opinion piece, according to Forbes.
Both Meyerowitz-Katz and Beck recommend pregnant women ignore the latest headlines and talk to their doctor if they have concerns about caffeine.
That said, since there’s still no clear information on how much caffeine is safe in pregnancy, erring on the side of caution and sticking to ACOG’s advice is a smart choice.
See BabyCenter’s article on caffeine during pregnancy for more information and lists showing the amount of caffeine in common drinks and food.