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 very small 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, there is a greater risk of miscarriage, still birth or birth defects.

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-stage pregnancy, it is more common for the infection to pass to the baby. For example:

  • if you become infected around the time of conception, there is less than a 1% 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 70% chance that your baby will also be infected

However, babies infected during later-stage 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 2010 study showed that, in non-immune women (those who haven't had the infection before), about 5 per 1,000 may get a toxoplasma infection, with a 10-100% risk of transmission to the baby. A study has suggested that, in the UK, about 3 in every 100,000 babies are born with congenital toxoplasmosis.

Congenital means it is present from birth.

Read more information about toxoplasmosis, including symptoms, diagnosis and treatment.

Avoiding toxoplasmosis infection

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

For more information, see Why shouldn’t I change the cat litter during pregnancy?

Read the answers to more questions about infections during pregnancy.

Further information:

Page last reviewed: 03/05/2014

Next review due: 02/05/2016