In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to psilocybin mushrooms may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What are Psilocybin mushrooms (“magic mushrooms”)?

The term magic mushrooms refer to mushrooms with hallucinogenic properties (causing changes in your reality) that are taken as an illegal drug. Psilocin and psilocybin are the hallucinogenic components found in certain types of mushrooms. These psilocybin mushrooms are sometimes called other names such as caps, shrooms, and buttons. Magic mushrooms are usually eaten fresh or dried but may be brewed in a tea or added to food.

Can consuming magic mushrooms during pregnancy cause birth defects?

We can’t be sure. A single animal study showed no increased chance of physical birth defects, but without human studies, effects in pregnancy are not known.

Users of magic mushrooms also report using other drugs such as cocaine, Ecstasy, LSD, and non-prescribed prescription drugs which adds additional risk. Another concern is mistaking poisonous mushrooms for magic mushrooms which could lead to a medical emergency.

Can consuming magic mushrooms during pregnancy have an effect on my baby’s developing brain?

There have been no published studies on the long term effects of using mushrooms during pregnancy. At this time, it’s unknown if magic mushrooms can affect a baby’s brain or development. .

What are the dangers of consuming magic mushrooms while I am breastfeeding?

Magic mushrooms have not been studied for use during breastfeeding so the risks are not known. Be sure to talk to your health care provider about all of your breastfeeding questions.

What if the father of the baby uses magic mushrooms?

A man’s use of magic mushrooms has not been studied for effects on pregnancy. In general, exposures that the father has are unlikely to increase the risk to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures and Pregnancy at

Selected References:

  • Hallock RM, et al. 2013.A survey of hallucinogenic mushroom use, factors related to usage, and perceptions of use among college students. Drug Alcohol Depend. 130(1-3):245-8.
  • Rolsten C, 1997. Effects of chlorpromazine and psilocin on pregnancy of C57BL/10 mice and their offspring at birth. Anat Rec 157:311.
  • Timar L, Czeizal AE. 1997, Birth weight and congenital anomalies following poisonous mushroom intoxication during pregnancy. Reprod Toxicol 11: 861