Caffeine Intake During Pregnancy

Posted on Saturday, July 7th, 2018

Caffeine during Pregnancy: How much can you take?

When you’re pregnant everybody around you feel free to share advice on all sorts of things such as what foods to eat, what to avoid, and basically everything else. You’ve probably noticed that they share the advice even if you don’t ask them to do so. Unfortunately, many things we hear from other people aren’t necessarily true. Let’s take coffee as an example, pregnant women are told to completely avoid it, other women say you just need to limit intake, but there are also those who will tell you it’s perfectly safe. What is the truth? To help you go through your pregnancy stress-free, this post focuses on caffeine during pregnancy and its intake.

Caffeine crosses placenta barrier

The placenta is an organ that develops in your uterus during pregnancy to provide nutrients and oxygen to a growing baby while removing waste products from the baby’s blood. Basically, placenta protects and nourishes the baby and it is crucial to keeping your child alive and well throughout the pregnancy. Evidence shows that caffeine crosses placenta barrier and decreases placental blood supply, but more studies are needed to investigate this subject thoroughly. Although adults are able to effectively metabolize caffeine babies are not, particularly in early stages of development. This means that caffeine has a direct influence on tissues, cells, and membranes. For adults, these things are okay and that’s why we drink coffee (it’s a stimulant), but for babies, it’s not and it could interfere with their development.

Caffeine and risk of birth defects

The CDC reports that one in every 33 babies or 3% of all babies born in the United States has birth defects. High caffeine intake has been associated with increased risk of birth defects. According to the World Health Organization (WHO), excess consumption of caffeine could lead to growth restriction, preterm birth, stillbirth, and decreased birth weight. That said, studies on this subject yielded mixed results. For example, November 2008 issue of the BMJ published a study which discovered that caffeine consumption during pregnancy was strongly associated with an increased risk of fetal growth restriction and this link continued throughout pregnancy. This discovery was confirmed by a study from February 2013 issue of the BMJ Medicine. On the other hand, a research from 2011 found no relationship between caffeine and birth defects. This only shows the complexity of the problem and could explain why you get confusing tips from people around you. While many doctors and organizations confirm that excessive consumption of caffeine can lead to preterm birth, a meta-analysis of studies on this subject found no important link between the two. It’s safe to say that evidence on the relationship between caffeine and preterm is inconclusive, but you still need to be careful. Why? Studies show that excessive intake of caffeine during pregnancy was linked to the low birth weight of an offspring. It’s not just about coffee, caffeine from all sources such as tea, fizzy drinks, chocolate, and desserts can lead to low birth weight. For a baby of an expected average weight (3.6kg or 7.9lbs), this equates to 21-28g (0.7-0.9oz) lost per 100mg of coffee a day.

Does caffeine lead to miscarriage?

Similarly to birth defects, the relationship between caffeine and miscarriage is rather confusing. A study from the American Journal of Obstetrics and Gynecology found that high doses of caffeine intake during pregnancy enhance the risk of miscarriage, independent of pregnancy-related symptoms. On the other hand, a research from the Epidemiology journal showed that there is little indication of potential harmful effects of caffeine on the risk of miscarriage. That said, scientists explained their subjects reported caffeine intake so there is always the chance that someone didn’t provide accurate results. National Institutes of Health conducted a study which yielded some interesting outcomes. Scientists discovered that a woman is more likely to miscarry her baby if she and her partner drink more than two caffeinated beverages per day during the weeks prior to the conception. This study also revealed that women who drank more than two caffeinated drinks a day during the first seven weeks of pregnancy were also at a higher risk of miscarrying their baby.

Should pregnant women avoid caffeine entirely?

Bearing in mind that studies show mixed results and a growing body of evidence confirms negative impact of caffeine, it’s impossible not to wonder whether pregnant women should avoid caffeine entirely. If you can’t imagine starting your day without coffee, you’ll be pleased to know that you can limit caffeine consumption, not avoid it completely. The American College of Obstetrics and Gynecology confirms that moderate intake of caffeine (less than 200mg a day) doesn’t appear to be a major contributing factor in preterm birth and miscarriage. In addition, WHO recommends that women who drink too much caffeine (more than 300mg per day) should lower the consumption in order to effectively reduce the risk of birth defects and pregnancy loss. At the same time, the American Pregnancy Association recommends that pregnant women should strive to avoid caffeine as much as possible during pregnancy and breastfeeding. If you can’t ditch coffee, then moderate consumption of 150-200mg a day is enough.

Amount of caffeine in foods and beverages

Although the word caffeine makes us think of coffee only the compound is found in other beverages and foods. Limiting caffeine intake also means that you should be careful when eating or drinking other sources of the compound. This table can help you.  
Food/beverage Amount Caffeine
Coffee (generic, brewed) 8oz 95-200mg
Coffee (Starbucks, brewed) 12oz 240mg
Espresso (generic) 1oz 64mg
Black tea (brewed) 8oz 47mg
Green tea (brewed) 8oz 25mg
Coke 12oz 35mg
Diet coke 12oz 47mg
Pepsi 12oz 38mg
Red Bull 8.3oz 77mg
Dark chocolate 1oz 23mg
Milk chocolate 1.55oz 9mg
Hot cocoa 8oz 8-12mg
Chocolate chips (semisweet) 4oz 53mg

Conclusion

High intake of caffeine is linked to birth defects, miscarriages, preterm birth, and other consequences. That said, studies still yield conflicting results that only show how complicity of the subject. Caffeine can cross the placenta and the baby can’t metabolize it like adults so negative impact is not a shocker when you think that way. It’s recommended to consume up to 200mg a day to avoid negative effects.
References 

https://www.sciencedirect.com/science/article/pii/0002937883902508

http://content.time.com/time/health/article/0,8599,1731087,00.html

https://www.cdc.gov/ncbddd/birthdefects/data.html

http://www.who.int/elena/titles/caffeine-pregnancy/en/

http://www.bmj.com/content/337/bmj.a2332

https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-42

https://www.ncbi.nlm.nih.gov/pubmed/21254365

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2954446/

https://www.sciencedaily.com/releases/2013/02/130218201513.htm

https://www.ncbi.nlm.nih.gov/pubmed/18221932

https://www.ncbi.nlm.nih.gov/pubmed/18091004

https://www.nih.gov/news-events/news-releases/couples-pre-pregnancy-caffeine-consumption-linked-miscarriage-risk

https://www.acog.org/Clinical-Guidance-and-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Moderate-Caffeine-Consumption-During-Pregnancy

http://americanpregnancy.org/pregnancy-health/caffeine-intake-during-pregnancy/

https://www.babycenter.com/caffeine-during-pregnancy