A pregnant woman texts on her phone while holding a cup of coffee.
Caffeine may affect you differently during pregnancy since your body can't metabolize it as quickly.Johner Images/Getty Images
  • The ACOG recommends no more than 200 mg/day of caffeine for people who are pregnant.
  • Caffeine during pregnancy has been linked to lower birth weight, but other factors may play a part.
  • Energy-boosting alternatives to caffeine include whole grains, hydration, and plenty of rest.
  • Visit Insider's Health Reference library for more advice.

Pregnant people might make any number of dietary choices to help protect the health of their developing baby, including reducing their coffee intake or giving it up altogether.  

Exactly how the caffeine in coffee affects fetal development is unclear. What is known is that caffeine can cross the placenta and fetuses don't have the specific enzymes needed to metabolize caffeine. 

Moreover, your body can't metabolize caffeine as quickly during pregnancy, meaning it will stay in your bloodstream longer. 

For those reasons, experts suggest erring on the side of caution when it comes to consuming coffee, and other caffeinated foods and drinks, while pregnant.

Below, experts share how caffeine could affect your pregnancy and offer recommendations on what's safe to consume.

Is there a safe amount?

The American College of Obstetricians and Gynecologists (ACOG) caps the caffeine limit for pregnant people at 200 milligrams per day (mg/day). Any more than that is associated with an increased risk of miscarriage.

That said, it's relevant to note a 2021 study, which found that pregnant participants who consumed the caffeine equivalent of just half a cup of coffee a day — 50 mg — had slightly smaller babies (about 2.3 ounces lighter) than those who didn't have any caffeine. 

These findings are important because babies with low birthweight may have a harder time fighting off infections and an increased risk of complications like neurologic disorders and breathing problems. 

It's important to note that the study didn't conclude that low doses of caffeine are directly harmful to the baby — just that caffeine intake may result in a slightly smaller size at birth. 

So what's the overall consensus? 

"Drinking below 200 milligrams is safe if a pregnant woman is able to tolerate coffee, meaning it's not causing onset nausea or sickness," says Jessica Shepherd, MD, an OB-GYN and Director of Minimally Invasive Gynecology at the University of Illinois at Chicago.

What about other caffeinated beverages? 

Some teas, soft drinks, and energy drinks also contain caffeine, though not as much as coffee: 

Keep in mind: The amount of caffeine in tea can vary significantly depending on the variety, origin, and even how long you steep it. 

Herbal teas like chamomile, peppermint, and lemon ginger have no caffeine at all. However, decaf coffee and tea can still have small amounts of caffeine — usually less than 12 mg per 8-ounce serving.

Caffeine from other sources

Caffeine can also be found in small amounts in some foods. 

Cacao beans, which are used to make chocolate, naturally contain caffeine. The darker the chocolate, the higher the cocoa content and thus, caffeine level. 

For example, a 100-gram serving of 70% to 85% dark chocolate contains 80 mg of caffeine, while the same amount of milk chocolate only contains 20 mg of caffeine. 

Even coffee- and chocolate-flavored foods, like ice cream, cake, frosting, and cereal, can contain trace amounts of caffeine.

Some supplements and over-the-counter pain relievers contain caffeine as well, says Renita White, MD, a board-certified OB-GYN with Georgia OB-GYN. Excedrin Migraine, for instance, contains 65 mg of caffeine per caplet, and Midol Complete contains 60 mg of caffeine per caplet.

"Any medications you're thinking about taking, including over-the-counter drugs, should definitely be discussed with your doctor to ensure they are safe to take while pregnant," says Shepherd.

Caffeine's potential effects during pregnancy

While some studies have suggested that caffeine has an adverse effect on birth weight, others haven't found a significant link between the two. 

In a large 2013 study, researchers noted that evidence for the association between caffeine intake and fetal development is limited since studies haven't taken into account other factors, such as smoking — which is strongly correlated to caffeine consumption and known to increase the risk of preterm delivery and low birth weight.

On the flip side, in the same 2021 study discussed earlier, researchers noted that caffeine may cause blood vessels in the uterus and placenta to constrict, which could reduce blood supply to the fetus, affecting its growth. 

Studies also suggest caffeine may alter the baby's stress response and hinder organ development.

"Since the baby is still developing, their body and nervous system are not mature enough to handle caffeine the same way an adult could," says Shepherd. "If too much caffeine is consumed during pregnancy, their heart rate may increase, leading to potential sleep disturbances."

You may also want to consider caffeine intake based simply on how you respond to it because you are likely to be more sensitive to the effects of caffeine during pregnancy since it takes longer to clear from your body, says White.

You might notice: 

What to try instead

If you use caffeine as an energy booster, consider these alternatives to coffee and other caffeinated foods and beverages:

  • Whole grains: Your body converts carbohydrates into glucose, which it uses for energy. Whereas the carbs found in many processed foods are digested quickly, resulting in a rapid burst of energy followed by an inevitable crash, complex carbs are digested more slowly and offer a more steady supply of energy. That's why Shepherd recommends eating complex carbs like oatmeal, brown rice, sweet potatoes, and legumes.
  • Foods with folate: Also known as vitamin B9, folate helps the body convert carbohydrates into glucose for fuel. Beans, avocado, dark leafy greens, and many other vegetables are high in this essential nutrient. It's also worth mentioning that getting enough folate during pregnancy is key for preventing certain birth defects, so your doctor or midwife will likely recommend a prenatal supplement.
  • Magnesium: Magnesium is another mineral that helps to convert food into energy. Magnesium-rich foods to try include pumpkin seeds, almonds, cashews, peanuts, and black beans.
  • Plenty of water: Dehydration can cause feelings of fatigue, lethargy, and sleepiness, says White. The ACOG recommends drinking eight to 12 cups, or 64 to 96 ounces, of water daily during pregnancy.

Keep in mind, though, that it's perfectly normal to feel fatigued during pregnancy. This will pass, so let your body rest when you feel tired.  

Insider's takeaway

Experts recommend consuming less than 200 mg of caffeine per day in order to minimize any potential risks for you or your developing baby. 

That means sticking to about one cup of coffee or two cups of caffeinated tea a day or switching to herbal tea, decaf coffee, or decaf tea. 

Caffeine can also affect people differently, so when in doubt, Shepherd and White advise speaking with your doctor or midwife about how much caffeine is safe for you.

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