What Is Congenital Toxoplasma?


In this Article

  • Causes of Congenital Toxoplasma
  • Signs of Congenital Toxoplasma
  • Diagnosing Congenital Toxoplasma
  • Risks of Congenital Toxoplasma to Babies
  • How to Prevent Congenital Toxoplasma

Toxoplasmosis is an infection caused by the presence of the Toxoplasma gondii parasite. It’s attracted to warm-blooded mammals and can be found in both animals and humans. 

Congenital toxoplasma occurs when a pregnant woman gets infected by these parasites and passes them on to her fetus.

Causes of Congenital Toxoplasma

There are three main ways for humans to become infected with the parasites that cause toxoplasma:

  • Eating raw or undercooked meat infected with T. gondii parasites
  • Coming into contact with cat feces that contain an environmentally resistant version of T. gondii parasites
  • Drinking water contaminated by T. gondii parasites
  • Eating unwashed produce infected with T. gondii parasites

Women who are further along in their pregnancy become infected faster. Around 65% of women in their third trimester transmit the infection to their baby. If infected earlier in pregnancy, the transmission rate is lower at 25%. 

Overall, approximately 30% to 40% of women who become infected during pregnancy will pass the infection on to their baby.

Signs of Congenital Toxoplasma

Pregnant women who become infected with T. gondii parasites usually don’t show signs of being ill. However, those that do, often have symptoms similar to mononucleosis. Some pregnant women end up with swollen lymph nodes or red and inflamed eyes.

They may feel sick for a few months before the condition clears up. The parasites remain in their system in an inactive state and can reawaken if a person’s immune system becomes compromised.

Fetuses infected with T. gondii parasites typically don’t exhibit obvious symptoms but may end up developing the following issues in the womb or after delivery:

  • Intrauterine Growth Restriction (IUGR) or Fetal Growth Restriction (FGR), in which a baby doesn’t grow at a normal rate inside the womb
  • Myocarditis, which involves inflammation in the heart
  • Rashes
  • Enlarged liver and spleen
  • Seizures
  • Fluid in the brain

Diagnosing Congenital Toxoplasma

There are various tests available to detect T. gondii parasites in both the mother and child. Your doctor may test you for congenital toxoplasmosis if they notice any abnormalities on a sonogram or suspect that you have an acute infection brought on by an organism.

If your doctor suspects that you have contracted congenital toxoplasma, they may start by ruling out other causes like the Epstein-Barr virus or HIV. The tests administered to check for the presence of T. gondii parasites typically look for increased levels of certain antibodies.

When it comes to the fetus, your physician may order a PCR analysis (which looks at DNA samples) or other antibody tests.

Newborns with a suspected congenital toxoplasmosis infection typically undergo various methods to confirm the diagnosis, including:

  • Serologic tests to look for antibodies in the blood
  • CT brain imaging or MRI
  • Cerebral Spinal Fluid (CSF) analysis, which looks at fluid in the brain and spine
  • Eye exam
  • Brainstem auditory evoked response (BAER) test, which measures how the brain processes sound

Risks of Congenital Toxoplasma to Babies

If a woman becomes infected with T. gondii parasites before getting pregnant, the mother’s natural immunity typically protects her fetus from infection. Congenital toxoplasma can develop if the mother gets infected right before or during pregnancy. Infection by T. gondii parasites at such an early stage of the pregnancy can lead to complications like:

  • Miscarriage
  • Stillbirth
  • Babies born with an unusually large or small head

The prognosis for children born with congenital toxoplasma varies. Some may end up dying early. Others may go through life with various neurologic disorders and other impairments like poor intellectual development, deafness, or seizures. Children born with congenital toxoplasma should receive continuous monitoring after birth.

How to Prevent Congenital Toxoplasma

If you suspect that you’re pregnant, you’ll want to take the following measures to protect yourself from becoming infected with T. gondii parasites:

  1. Cook foods at a safe temperature. Use a food thermometer to track the internal temperature of meats.
  2. Peel and wash fruits and vegetables before eating them.
  3. Thoroughly clean dishes, utensils, counters, and other items before using them.
  4. Wash your hands with hot, soapy water before and after preparing food, especially meat.
  5. Cover your hands with gloves if you’re going to be working in your garden to reduce the risk of accidentally coming into contact with cat feces in the soil. Wash your hands thoroughly after gardening.
  6. If you own a cat, let someone else handle the job of changing its litter during your pregnancy. If you can’t avoid the task, cover your hands with gloves and wash your hands after.

Show Sources


American Academy of Pediatrics: “Diagnosis, Treatment, and Prevention of Congenital Toxoplasmosis in the United States.” 

Centers for Disease Control and Prevention: “Parasites – Toxoplasmosis (Toxoplasma infection),” “Preventing Congenital Toxoplasmosis.”

Journal of the Pediatric Infectious Disease Society: “Congenital Toxoplasmosis.”

Merck Manual: “Congenital Toxoplasmosis.”‌‌

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