This is a very common question and one that the obstetric community is still trying to figure out…which means we don’t have a definitive answer just yet.
Who doesn’t love a warm or iced Starbucks beverage on the way to work every day? There’s a reason you can find some sort of coffee establishment within a few miles of just about anywhere these days. But is all that caffeine ok during conception and pregnancy? We totally understand not wanting to give it up but many women simply aren’t sure how it might affect their chances of getting pregnant or a pregnancy once it happens. This is a very common question and one that the obstetric community is still trying to figure out… which means we don’t have a definitive answer just yet.
What we know about caffeine and pregnancy
Let’s start with what we do know though. First, we know pregnant women metabolize caffeine much more slowly than non-pregnant women. It can take up to 3.5 times longer for a pregnant woman to eliminate caffeine from her body. Caffeine is also known to cross the placenta and enter the baby’s bloodstream, which of course raises concerns.
Pregnant women metabolize caffeine much more slowly than non-pregnant women. It can take up to 3.5 times longer for a pregnant woman to eliminate caffeine from her body.
Many studies have been done on caffeine consumption in pregnancy but their results have unfortunately conflicted with each other. On the one hand, there are studies like this one done in 2015 that show a correlation between high levels of caffeine in pregnancy and babies with low birth weights. We care about low birth weight because it is linked to an increased risk of chronic medical problems later in life. There are some studies that also link high caffeine intake to miscarriage. In this meta-analysis, 26 studies were reviewed and the conclusion was that high caffeine intake did lead to an increased risk of pregnancy loss in a dose-dependent fashion (the more caffeine you consume, the higher your risk).
But on the other hand, there are also conflicting studies that show no relationship between caffeine intake, miscarriage, or later pregnancy outcomes. For example, one study found that caffeine intake was not related to preterm delivery or low birth weight. Another one found no relationship between caffeine and low birth weight.
A safe level of caffeine intake
So what’s a patient to do with all this conflicting information? Well, thankfully, all of the studies do agree on one thing--that caffeine at less than 200 mg per day is pretty safe. The American College of Obstetrics & Gynecology (ACOG) rounded up and reviewed all the literature out there and came to the conclusion that moderate caffeine consumption doesn’t seem to be a contributing factor in terms of miscarriage or preterm labor. The effect of caffeine at doses higher than 200 mg daily though is still undetermined and therefore can’t be recommended.
Moderate caffeine consumption doesn’t seem to be a contributing factor in terms of miscarriage or preterm labor.
The World Health Organization (WHO) seconds ACOG and recommends that pregnant women with high daily caffeine intake (more than 300 mg per day) lower their caffeine intake during pregnancy to decrease the risk of pregnancy loss and low birth weight babies.
So can I have my cup of coffee and eat my chocolate too?
Now let’s go through that practically—what does 200 mg of caffeine look like? As we know, caffeine is found naturally in things like tea, coffee, and chocolate. It’s now added to common products like energy drinks, cold and flu medications, and some sodas. But how much caffeine do each of these products contain? And does how the product preparation matter?
One cup (8 oz) of instant coffee is anywhere from 76-106 mg of caffeine, while brewed coffee is 135 mg. So if you get a 12 oz (tall) coffee from Starbucks or Dunkin Donuts, you’re already at a little over half of your daily intake of caffeine. Green tea has about 30 mg of caffeine in 1 cup. One can of a cola beverage, diet or regular, has between 36-46 mg. For things like energy drinks, it’s important to read the label and find out how much caffeine is in a serving--especially when the product comes in a large container that may be more than one serving. Red Bull has 111 mg of caffeine per serving.
It's your choice
What do I counsel my patients? At the end of the day, it’s their choice, but they can rest assured that as long as they’re staying around that 200 mg mark of caffeine consumption, they’re not hurting anything. So grab that Starbucks mocha peppermint frappuccino that you like so much, just keep track of what size and how many per day you’re drinking and you should be fine. Now, the amount of sugar in one of those is another story...