mythbuster graphic If you’ve ever wondered whether it was true that pregnant women should stay away from cats because their feces can cause birth defects, here’s the somewhat surprising answer: yes and no.

It turns out that cats do expel a parasite in their feces that can be harmful to a fetus. But this parasite is also easily contracted in other ways, not just through cats. And there are plenty of ways to prevent this parasite from affecting a fetus, so expectant mothers don't need to shoo away cats for fear of their babies' health.

Toxoplasmosis is an infection caused by a specific parasite which normally causes minimal symptoms or goes entirely undetected in most humans and animals. Cats spread the parasite via their feces after eating contaminated small animals like birds or rodents. While the cats are rarely affected by the infection, the parasites they expel are potentially dangerous to human pregnancy.

If a pregnant woman cleans an infected cat's litter box, she is exposed to the parasite. If the woman touches her mouth after coming in contact with the parasite, she may become infected and place her fetus is at risk for serious complications, either at birth or later in life.

At or before birth, the parasite can cause serious eye infections or other eye problems, brain damage, or even stillbirth or an aborted fetus. And while many babies infected with toxoplasmosis may not exhibit any symptoms at first, they may eventually suffer from blindness or intellectual disability as a result.

Any cat let outdoors or fed raw or undercooked meat may also carry the parasite. Any contaminated feces from cats that have contracted the infection are a danger to a woman’s pregnancy.