If you’re a mama-to-be, your doctor probably already told you to cut down on the caffeine. Studies have shown that caffeine may negatively affect your baby’s health, so giving up that morning cup of jo—or, at least, switching to decaf—is on the top of the list of diet changes. If you’re not a coffee drinker, then it may mean cutting back on soda or black tea.


Mamas-to-be don’t have to give up caffeine entirely, though. The American College of Obstetricians and Gynecologists currently recommends that pregnant women consume less than 200 milligrams of caffeine per day. According to the Mayo Clinic, that translates to two 8 ounce cups of coffee or up to four cups of soda.

Current research suggests that drinking more than 200 mg a day may increase a mama-to-be’s risk of low birth weight, preterm birth and pregnancy loss. But a new study published in BMJ Open found another possible side effect of very high caffeine consumption: A higher risk of excess weight gain in children.

According to the study, infants may be more at risk of excess growth during their first year of life, as well as being overweight as an adolescent, if their mom drank excessive amounts of caffeine, be it from coffee or black tea, during pregnancy. In addition to coffee, sources of caffeine can include soda, energy drinks, chocolate, chocolate milk, certain sweets and black tea.

Speaking to CNN, lead study author Eleni Papadopoulou, a researcher at the Norwegian Institute of Public Health, says, “It is important that pregnant women be aware that caffeine does not come from coffee only but that caffeinated soda drinks can also contribute with considerable amounts of caffeine.”

Researchers analyzed health data from more than 50,000 Norwegian women that included their caffeine intake during pregnancy and their children’s growth patterns from 6 weeks to 8 years old. What they discovered is that mothers who reported consuming a “very high” amount of caffeine had a 66% increased risk of having a child who scored greater than the 75th percentile for growth within their first year of life—what the researchers consider “excess growth.”

And that risk continued into adolescence. According to the study, children exposed to very high levels of caffeine during pregnancy were more likely to be overweight by 8 years old than kids exposed to low caffeine levels.

The study also found that, compared to pregnant women who consumed little caffeine, women who drank an average amount had a 10% heightened risk of excess growth during infancy. Women with high caffeine intakes had a 30% increase in risk.

“We considered it very important to study the effects [of caffeine] on infant growth, because rapid infant growth has been very consistently related to the development of obesity in childhood and even in adulthood,” Papadopoulou says. “In other words, children and adults who are gaining more weight during infancy than their peers are at higher risk to be overweight or obese.”

The findings, she continues, affirms medical wisdom advising women to stay away from caffeine while pregnant. But, she notes, the study also supports current ACOG recommendations that pregnant women shouldn’t drink more than 200 mg a day during those nine months. So, maybe don’t drink copious amounts of coffee, but a cup of decaf won’t hurt.

As for after pregnancy? Drink all the coffee your heart desires, mama. In fact, despite conventional wisdom that consuming a lot of caffeine may be bad, research shows that your coffee habit may actually benefit your health. One study published in The British Medical Journal in November found that a link between moderate coffee consumption and lower disease rates.

Specifically, British researchers discovered that people who drank up between three and four cups of coffee a day have a lower risk of developing cardiovascular disease, coronary heart disease, stroke, liver disease and certain cancers.

What’s more: A 2012 National Institutes of Health (NIH) study found that people who consumed at least three daily cups of coffee—which is rich in disease-fighting antioxidants—had a lower risk of death from heart disease, stroke, cancer and diabetes.Why coffee is linked to positive health benefits is unclear. According to NIH researchers, it may only reflect a causal relationship.

Still, if you’re a mama-to-be worried about your caffeine intake, speak with your doctor. Most pregnant people will gradually stop drinking coffee on their own as many can’t stomach the thought of it it, but if you’re lucky enough not to feel that way, you may want to set a limit on your intake.

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