What are the risks of toxoplasmosis during pregnancy?

If you get toxoplasmosis for the first time when you’re pregnant, or up to three months before you conceive, there’s a risk that the infection can:

  • pass to and damage your unborn baby (mother-to-child transmission)
  • cause miscarriage or stillbirth

The risk of problems varies, depending on when you become infected during your pregnancy.

Risk of miscarriage and health problems

If you get toxoplasmosis in the early stages of pregnancy, the risk of miscarriage is increased.

It’s rare for the infection to pass to the baby during early pregnancy but, if it does, it can cause serious health problems.

In later pregnancy, the infection more commonly passes to the baby. For example:

  • if you become infected around the time of conception, there is less than a 5% chance that your baby will also develop the infection
  • if you become infected during the third trimester of your pregnancy (from week 27 until the birth), there is about a 65% chance that your baby will also be infected

However, babies infected during later pregnancy are less likely to develop serious health problems.

How common is toxoplasmosis during pregnancy?

The risk of getting toxoplasmosis when you’re pregnant is very low. A 2008 study showed that, in nonimmune women (those who haven't had the infection before), about five per 1,000 may get a toxoplasma infection, with a 10-100% risk of transmission to the baby. One study suggested that, in the UK, about three in every 100,000 babies are born with congenital toxoplasmosis. Congenital means present from birth.

You can find more information about toxoplasmosis in our Health A-Z, including symptoms, diagnosis and treatment.

Avoiding toxoplasmosis infection

In the UK, pregnant women are not routinely screened for toxoplasmosis. It’s therefore important that you know how to prevent toxoplasmosis infection.

For more information, see Why shouldn’t I change the cat litter if I’m pregnant?

Read the answers to more questions about infections during pregnancy.


Further information:

Page last reviewed: 31/05/2012

Next review due: 30/05/2014