Page modified at: 14/03/2010
Toxoplasmosis and pregnancy
In the UK, approximately 2,000 women a year get toxoplasmosis while they are pregnant. If you catch toxoplasmosis while pregnant, you may have no, or just a few mild symptoms, such as a sore throat and a mild fever.
However, there is a chance that the toxoplasmosis infection will be passed on to your baby. This is known as congenital toxoplasmosis.
The time between catching toxoplasmosis and showing symptoms (the incubation period) is between 5-23 days and it can take between 4-8 weeks to pass the infection to your baby.
The risk of toxoplasmosis being passed to your baby varies depending on how far into your pregnancy you are when you become infected.
For example, the risk to your baby is estimated to be:
•between 10-15% if you catch toxoplasmosis during the first trimester of pregnancy (weeks 0-13), and
•as high as 70-80% if you catch toxoplasmosis during the third trimester of pregnancy (week 27 to birth).
How do you get toxoplasmosis?
Toxoplasmosis is a common infection that is caused by the parasite toxoplasma gondii.
Animals can catch toxoplasmosis from infected soil and the infection can be passed on to humans if they eat raw, or undercooked, meat, or contaminated knives, cutting boards and other utensils, and the digestive system and faeces of cats.
Fresh fruit, vegetables, salads, and unpasteurised milk - particularly unpasteurised goats' milk - can also be a source of toxoplasmosis.
It can also be passed on through the cleaning of cat litter trays or in contaminated soil when gardening.
It can't be passed on through person-to-person contact.
Lots of people have a mild form of toxoplasmosis at some point in their life without realising it because there are often no symptoms. If you get the infection, you will become immune to it from then on.
Possible health implications
Congenital toxoplasmosis can cause several health problems, such as a higher-than-normal risk of miscarriage or an increased chance of a child developing eye infections or learning difficulties, later in life.
The way that congenital toxoplasmosis will affect your baby also depends on the stage of your pregnancy that the infection occurs. The earlier in your pregnancy you are when you become infected by the toxoplasmosis bacteria, the more severe the effect on your baby may be.
So although your baby is less likely to contract toxoplasmosis during the first trimester, they are more likely to be affected by serious health problems, or miscarriage, if they do. Babies who are infected later during pregnancy are less likely to develop serious health problems.
Advice for pregnant women
If you're pregnant, the following advice will help you to avoid coming into contact with toxoplasmosis.
•Avoid gardening or changing cat litter. If you must do these activities, wear gardening gloves, and wash your hands thoroughly afterwards.
•If you have a cat, make sure that its litter is changed daily (although you should not do it yourself), and do not feed your cat raw or undercooked meat.
•Do not handle stray cats.
•Wash your hands thoroughly after handling raw meat.
•Avoid eating cured meats, such as Parma ham and salami.
•Make sure that all meat is cooked thoroughly and is piping hot before eating it.
•Wash fruit, vegetables and salads before eating them.
•Do not drink unpasteurised milk or eat other unpasteurised dairy products.
•Toxoplasmosis is quite common in sheep. If you live near or work on a farm, don't handle lambing ewes, their afterbirth, newborn lambs or the clothing of anyone who is involved in lambing.
Most people who are infected with toxoplasmosis have no symptoms and don't know that they are infected.
After having a blood test, you will usually have to wait three weeks to see if you have caught the toxoplasmosis infection. If you have caught it, you may be given an antibiotic called spiramycin to reduce the risk of passing the infection on to your baby.
If you're more than 15 weeks pregnant, you may have an amniocentesis test (where fluid is taken from around the baby in the womb) and an ultrasound scan to see if the infection has been passed to your baby. If so, you may have treatment with antibiotics, such as pyrimethamine and sulfadiazine, to reduce the severity of your baby's infection.