What is toxoplasmosis?

Toxoplasmosis is an infection you can get from a microscopic parasite called Toxoplasma gondii. Although the infection generally causes a mild, symptomless illness in people with healthy immune systems, it's risky during pregnancy because the parasite may infect the placenta and your unborn baby.

Researchers estimate that of the over 4 million births in the United States each year, between 400 and 4,000 babies are born with toxoplasmosis (known as congenital toxoplasmosis). This infection can be mild or severe, causing stillbirth, long-term structural and neurological damage, and other devastating effects. The good news is there's a lot you can do to avoid becoming infected in the first place.

What are my chances of getting toxoplasmosis and infecting my baby?

Only about 15 percent of women of childbearing age are immune to toxoplasmosis, according to the Centers for Disease Control and Prevention (CDC). Fortunately, the number of women who contract the infection during pregnancy is still relatively small, and not all of them transmit it to their babies.

Your baby's risk of becoming infected rises as your pregnancy progresses. If you get infected with toxoplasmosis in the first trimester, the risk that your baby will also be infected is about 15 percent. If you get infected in the second trimester, your baby's risk is about 30 percent, and it's 60 percent in the third trimester. However, while the transmission rate is higher in late pregnancy, toxoplasmosis is more likely to be severe for your baby if he becomes infected in the first trimester.

There's also a very small risk of infecting your baby if you contract the infection within a few months before becoming pregnant. If you know that you've been infected recently, some experts suggest waiting for six months before trying to conceive.

How is toxoplasmosis spread?

Experts estimate that about half of toxoplasmosis infections are caused by eating raw or undercooked infected meat, but you can also get the parasite by eating unwashed contaminated produce, drinking contaminated water, or handling contaminated soil, cat litter, or meat and then touching your mouth, nose, or eyes.

Toxoplasmosis can't be transmitted from person to person, with the exception of transmission from mother to baby during pregnancy or from an infected blood transfusion or organ transplant.