The Effects of Caffeine During Pregnancy

The excessive intake of caffeine during pregnancy can have harmful effects. However, did you know that moderate consumption can actually be beneficial?
The Effects of Caffeine During Pregnancy
Sara Viruega Encinas

Written and verified by the pharmacist Sara Viruega Encinas.

Last update: 27 December, 2022

Caffeine is a substance that our society consumes quite habitually. It’s present in coffee as well as chocolate, soft drinks, and tea, for example. However, consuming caffeine during pregnancy is a controversial topic. Today, we’ll take an in-depth look at this issue.

What is caffeine?

We talk about caffeine all the time, but do we really know what it is? Chemically, it’s an alkaloid that belongs to the methylxanthine group. In our bodies, caffeine acts in the central nervous system as a psychostimulant.

It’s a competitive antagonist of the A1 and A2a receptors of adenosine. These receptors are responsible for inhibiting the release of many neurotransmitters. Therefore, the effect of caffeine is the release of these same transmitters. This maximizes, among other things, the action of dopamine.

Caffeine is also considered to be a drug of abuse, given its energizing and stimulating properties. Excessive consumption of caffeine on a regular basis produces tolerance. At the same time, giving up a caffeine habit suddenly can lead to abstinence.

Caffeine is also used for its pharmacological properties. In particular, caffeine contributes to the analgesic treatment of pain. It also makes up part of the composition of many anti-flu and migraine medications.

The Effects of Caffeine During Pregnancy

What are the properties of caffeine?

As we’ve said, caffeine is a psychostimulant and psychoactive substance for our central nervous system. This means that it activates our brain, waking it up and keeping us alert. But that’s not all. Caffeine has other effects on our bodies as well, including the following:

  • Caffeine is an antioxidant and attacks free radicals.
  • Increases arterial pressure.
  • Increases heart rate.
  • Has diuretic properties.
  • Boosts the circulation of blood.
  • Can produce a certain level of dehydration.
  • Can produce headaches, though it can also help to relieve them.
  • Improves respiratory function by increasing the contraction of the diaphragm.
  • Produces vasodilatation on a muscular level.

The effects of caffeine during pregnancy

On occasion, caffeine has been considered a risk factor when it comes to fertilityjust like tobacco and other drugs. Small doses, however, don’t pose a risk. Just the same, it’s an important piece of information to keep in mind to avoid abuse if you’re looking to conceive.

The Effects of Caffeine During Pregnancy

Moderate consumption of caffeine during pregnancy doesn’t cause harmful effects. That being said, drinking high amounts of caffeine while pregnant can reduce fetal growth and even lead to miscarriage.

Why is this so? Caffeine passes through the fetus, meaning that the amount of caffeine in a mother’s blood can flow freely into amniotic liquid and to the fetus.

In the placenta, there is no way to metabolize the caffeine that gets in. At the same time, the fetus lacks the necessary enzymes in its liver until it reaches 8 months of gestation.

Due to the properties of caffeine, it can cause uterine and fetal vasoconstriction, reducing the amount of blood that arrives. This means the baby gets less oxygen and fewer nutrients. Therefore, elevated intake of caffeine can alter fetal growth.

Another more serious complication that caffeine can cause during pregnancy is miscarraige. This is especially true during the first trimester. Excess caffeine can also cause the appearance of preeclampsia or hypertension.

Arterial hypertension and heart rate are factors that are important to control during pregnancy. Therefore, it’s important to avoid consuming substances that can alter these numbers. Failing to do so can lead to undesirable complications, both for mother and baby.

At the same time, during lactation, caffeine can also pass from a mother to her baby via breast milk. Excessive intake of caffeine in breastfeeding mothers can produce irritability in babies as well as alterations in their sleep. However, moderate consumption isn’t a risk.


All of this being said, there is still a lot of research to be done on this subject. It’s true that the abuse of caffeine is harmful, especially during pregnancy, for both mother and baby. However, moderate consumption is harmless, and can even be beneficial .

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Pardo Lozano, R., Alvarez García, Y., Barral Tafalla, D., & Farré Albaladejo, M. (2007). Cafeína: un nutriente, un fármaco, o una droga de abuso. Adicciones: Revista de socidrogalcohol19(3), 0225-238.
  • Valenzuela, A. (2010). El café y sus efectos en la salud cardiovascular y en la salud materna. Revista chilena de nutrición37(4), 514-523.
  • Barreda-Abascal, R., Molina, L., Haro-Valencia, R., Alford, C., & Verster, J. C. (2012). Actualización sobre los efectos de la cafeína y su perfil de seguridad en alimentos y bebidas. Revista Médica del Hospital General de México75(1), 60-67.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.