Think you need to give up your morning cup of java if you’re pregnant? Not necessarily. Despite conflicting reports over the last 30 years, a recent meta-analysis article published in the American Journal of Clinical Nutrition did not find a significant association between caffeine intake and the risk of preterm birth.
According to the authors, as many as 13 percent of U.S. babies are born prematurely. Premature birth is a big public health concern, as it can lead to developmental issues, breathing difficulty, digestive problems at birth, as well as high blood pressure and low levels of insulin in later life. Previous research has shown that caffeine can cross the placenta to the fetus, and it is metabolized more slowly as the pregnancy progresses. As a result, the impact of caffeine on pregnancy outcomes has been a research topic of interest for decades.
The research team analyzed studies that looked at the relation between caffeine intake and preterm birth. Upon assessing the 22 studies that met the review criteria, caffeine intake levels were categorized from lowest (0 mg per day) to highest (greater than 300 mg per day). As a context, average caffeine content of common beverages are as follows:
- Typical home brewed coffee, 8 oz. (1 cup) – 95 to 200 mg
- Decaffeinated coffee, brewed, 8 oz. (1 cup) – 2 to 12 mg
- Starbucks® Vanilla Latte, Grande, 16 oz. – 150 mg
- Black tea, brewed, 8 oz. – 40 to 120 mg
- Red Bull® energy drink, 8.3 oz. – 76 mg
- Monster® Energy drink, 16 oz. – 160 mg
- Diet cola, 12 oz. can – 23 to 54 mg (Note that while the caffeine levels in diet drinks are not especially high, keep in mind that, as we recently reported, diet drinks contain artificial sweeteners, which may be independently associated with increased risk of premature birth.)
When they pooled all of the studies’ data together, the researchers found that the risk of preterm birth was not significantly higher in the “high caffeine” intake group compared to the caffeine-free group. This lack of an association was consistent when researchers cut the data to look at coffee-only intake and tea-only intake, as well as the total caffeine intake overall.
Although this study found no increased risk of preterm birth from moderate caffeine intake in pregnancy, most reputable authorities recommend limiting caffeine intakes during pregnancy to no more than 200 or 300 mg per day, partly due to conflicting evidence over the risks of miscarriage associated with higher caffeine intakes. While this new data may not have solved the debate once and for all, it does appear you can enjoy a daily cup of coffee during pregnancy without too much worry. Just remember to factor in the caffeine from other sources in your diet as well… they can add up quickly!