Can I Drink Coffee When Pregnant? What Science Says

This article is an excerpt from the Shortform summary of "Expecting Better" by Emily Oster. Shortform has the world's best summaries of books you should be reading.

Like this article? Sign up for a free trial here.

The first thing we’ll discuss is common vices that people generally advise to stop during pregnancy – caffeine, alcohol, and tobacco.

There’s a lot of stigma and confusion around the use of substances in pregnancy. In perhaps the most provocative part of Expecting Better, Oster argues that caffeine and alcohol, in moderation, show no evidence of being harmful to the child.

Caffeine During Pregnancy

The concern with caffeine is that it can increase risk of miscarriage and limit blood flow to the placenta.

The evidence is mixed – some studies find a 25% miscarriage rate for >200mg caffeine a day (about 1-2 cups of coffee), and 13% miscarriage rate for less caffeine consumption. High rates of caffeine (>5 cups of coffee a day) more consistently led to 50-100% increase in risk of miscarriage. 

Other studies find no relationship in miscarriage or baby health. Tea and cola are less consistently linked with miscarriage than coffee, which is odd since they all caffeine as the active ingredient. Furthermore, decaf coffee may be as strongly linked to miscarriage as regular coffee.

Oster argues that caffine pregnancy studies have a big confound with nausea. Nausea is apparently a good sign about the health of pregnancy and indicates a lower risk of miscarriage. However, you’re less likely to drink coffee when nauseated. So women who drink caffeine may simply be less nauseous and become more likely to have miscarriages.

Oster believes it’s completely safe to have up to 2 cups of coffee a day, and probably OK to have 3-4 cups. Beyond that, the evidence is mixed and may be confounded with nausea.

Can I Drink Coffee When Pregnant? What Science Says

———End of Preview———

Like what you just read? Read the rest of the world's best summary of "Expecting Better" at Shortform. Learn the book's critical concepts in 20 minutes or less.

Here's what you'll find in our full Expecting Better summary:

  • Why much parenting advice you hear is confusing or nonsense
  • The most reliable way to conceive successfully
  • How much alcohol research shows you can drink safely while pregnant (it's more than zero)
  • The best foods to eat, and what foods you really should avoid

Allen Cheng

Allen Cheng is the founder of Shortform. He has a passion for non-fiction books (having read 200+ and counting) and is on a mission to make the world's best ideas more accessible to everyone. He reads broadly, covering a wide range of subjects including finance, management, health, and society. Allen graduated from Harvard University summa cum laude and attended medical training at the MD/PhD program at Harvard and MIT. Before Shortform, he co-founded PrepScholar, an online education company.

Leave a Reply

Your email address will not be published. Required fields are marked *