Caffeine can be an easy way to beat pregnancy fatigue, but is it the right choice?
You’ve probably heard that caffeine can be bad during pregnancy, but is that true? If so, should you limit your intake or cut it out completely?
In this post, we’re diving into what the science says about drinking caffeine during pregnancy. We’ll cover whether your limit depends on trimester and list examples of what that limit actually looks like in terms of beverages.
Should You Have Caffeine When Pregnant? Here’s the Science
There is reason to be concerned about your caffeine intake during pregnancy. That’s because there’s a growing body of evidence that larger amounts could have harmful effects.
Before we jump into the studies, let’s consider some general facts:
- Caffeine crosses the placenta and enters the baby’s bloodstream—meaning that it has the potential to affect your baby.
- Pregnant women tend to metabolize caffeine at a slower rate. This means it stays in the body longer.
- Besides caffeine affecting the baby, it may have consequences for you too. Side effects include high blood pressure, jitters or anxiety, fast heart rate, restlessness and diarrhea.
- Even for some people, caffeine can cause the negative effects listed above. For an unborn baby who’s much smaller than us, it’s understandable why the effects could be more severe.
Caffeine During Pregnancy: Study Breakdown
When compared to no caffeine, a 2008 study found that a daily increasing dose was associated with an increased risk of miscarriage. Authors said the association appeared to be stronger if the women hadn’t had a miscarriage before.
A large Norwegian cohort study published in 2013 concluded that coffee—but not caffeine—was associated with increased gestational length but not preterm delivery. All forms of caffeine, such as chocolate and tea, were associated with low birth weight. Compared to women who had 50mg of caffeine/day or less, those who consumed between 200 to 300 mg/day were at an increased risk for their fetus being smaller than normal.
A 2014 scientific review of 13 studies concluded that higher caffeine intake was associated with increased low birth weight risk. They said the evidence supports restricting caffeine intake during pregnancy to low levels only.
Similarly, a 2015 study found that a high amount of caffeine is associated with a significant increase in low birth weight risk. The risk appeared to increase as caffeine intake did. More specifically, they calculated that for every additional 100mg of caffeine, the risk went up 3%. They defined 100mg as being one cup of coffee or 2 cups of tea.
A 2019 Korean study found that although there was an association between caffeine and bleeding, there wasn’t a significant increase in miscarriage risk.
What’s even more alarming is that one 2020 study found that caffeine triggered cardiometabolic defects on rodents’ babies and babies in future generations. Of course, it’s still unclear whether caffeine will have the same multigenerational effect in humans.
There’s something else to consider too: could maternal caffeine impact your child as they grow up? One 2019 study out of The Netherlands found that high caffeine intake during pregnancy was associated with children having a higher body mass index (BMI) and total body fat. The evidence suggests that the fat accumulated in specific deposits, which may increase the child’s risk of cardiometabolic disease later in life.
What Does It All Mean?
Considering all of the information we have, we don’t know enough to say how caffeine affects pregnancy. Although many studies have shown an association, they don’t necessarily show causation. There’s still not enough evidence to definitively say that caffeine increases the risk of preterm birth or miscarriage. We also don’t know what may be causing the connection in the studies. For example, it’s known that caffeine can increase blood pressure. High blood pressure is known to cause pregnancy complications. Or, different forms of caffeine may be more harmful than others.
While we can’t yet determine that caffeine causes specific complications, most experts say there’s enough evidence to at least limit your intake to below 200mg a day.
How Much Caffeine Should You Drink During Pregnancy?
First, you should ask your doctor about any dietary advice during pregnancy. If you’re at a higher risk, they may suggest forgoing it altogether.
The American College of Obstetricians Gynecologists (ACOG) recommends limiting your caffeine intake to 200mg a day during pregnancy. Similarly, the March of Dimes suggests sticking to two cups of coffee per day when breastfeeding. They also make the same recommendation for those trying to conceive. This recommendation of 200mg falls in line with what some studies have suggested; that more may lead to an increased risk.
With that being said, there’s some evidence that even a smaller amount could have impacts. For example, in the 2015 study we discussed above, even drinking one cup (100mg) could be increasing low birth weight risk by 3%. For that reason, some women play it safe and cut caffeine out completely. However, that may be difficult considering that caffeine isn’t just in coffee. It can also be found in foods such as dark chocolate. Decaf beverage varieties also still have small amounts of caffeine.
To summarize, you should limit your caffeine intake to 200mg per day. If you want to be extra safe, aim to further limit or completely cut out caffeine.
Caffeine and Pregnancy First Trimester: Does Fetus Age Matter?
You may wonder about caffeine and pregnancy in the first trimester since that’s a big stage of baby development. However, since it’s unclear how caffeine affects pregnancy, it’s unclear which stages may be most impacted. Although we have information on the complications experienced by pregnant heavy coffee drinkers, we have less data on what happens during the first, second and third trimesters.
One 2020 study on rodents showed that caffeine had an effect during specific stages, suggesting that it may depend on pregnancy timing in humans too. A 2019 Korean study found that heavy coffee drinking was associated with a higher risk of bleeding during early pregnancy.
The recommendation of limiting your intake to 200mg per day is for your entire journey. Some women may hope that caffeine during pregnancy in the second trimester is less harmful. However, you should still limit your intake even into breastfeeding.
Here’s What Your Pregnancy Caffeine Limit Looks Like
Now that you know you should limit your intake to 200mg per day, what does that exactly look like? Here’s a list so you don’t need to guess. Feel free to bookmark this page or save this link so you can refer to this list as a general guide whenever you’re gauging caffeine content.
200mg/day Looks Like*:
- 2 small cups of normal strength coffee (avg. 100mg each)
- 8 cans of coke (though we don’t recommend drinking this many, they have 29mg each).
- 2 Pints of Ben & Jerry’s Coffee Buzz Ice Cream (72 mg each)
- 4 cups 6 oz. of green or black tea (about 40-45mg each)
- 5 oz. of 80% cocoa dark chocolate
- 2 Tall Starbucks Iced Coffee with milk (90mg each) (remember no milk means more caffeine!)
- 2 short Caffe Misto (75mg each)
- 1 Short Starbucks coffee (high caffeine blends, 180mg each)
- 2 Short or Tall hot expresso drinks (i.e. latte, mocha) (75mg each)
*What to Consider
This caffeine content list gives you general estimates. Amounts will vary across product varieties. For example, you may be served or you may purchase a higher caffeine coffee blend, accidentally upping your intake. Be sure to check the label or ask the barista to be sure.
You should also consider checking the label when something contains coffee or dark chocolate flavor. Depending on how natural the flavor is, you may need to factor that into your daily intake.
The best way to know how much caffeine you’re having a day is to write down the caffeine products you typically eat or drink. Then, either make a mental note or write down whenever you consume it. Over a few days, you’ll have an idea of what your general caffeine intake is and how much you need to cut down.
Summary on Caffeine During Pregnancy Trimesters
There’s not enough evidence to say how caffeine affects pregnancy. Some studies show that in higher amounts, it may be associated with preterm birth and/or miscarriage. Although the connection isn’t clear, most experts, including the ACOG, recommend keeping caffeine intake to below 200mg per day. This is usually around 2 cups of normal strength coffee. However, be careful about high-caffeine varieties that may be served in cafes. Caffeine can also be found in foods such as dark chocolate or coffee flavors, so be sure to factor that in too. Some women prefer to play it safe by aiming well below the 200mg limit.
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