Toxoplasmosis infection during pregnancy

What Is Toxoplasmosis?

Toxoplasmosis is an infection caused by a parasite called Toxoplasma gondii. While it often causes no symptoms or only mild, flu-like symptoms in healthy adults, it can be serious if you get it during pregnancy because the infection can be passed to your unborn baby.

Why Is Toxoplasmosis a Concern in Pregnancy?

If you catch toxoplasmosis for the first-time during pregnancy, there is a chance you could pass the infection to your baby.

Infection can increase the risks of:

• miscarriage or stillbirth and

• may cause health problems for the baby such as eye or brain damage, hearing loss, seizures, delayed development, or

• may even cause severe illness for the baby at birth.

How Do People Get Toxoplasmosis?

You can become infected by:

- Eating raw or undercooked meat (including meat showing any traces of pink or blood)

- Eating dried/cured meats such as salami or Parma ham

- Consuming unwashed fruit or vegetables contaminated by soil or cat faeces

- Drinking unpasteurized goat’s milk or products made from it

- Handling cat litter/trays or soil contaminated by infected cat faeces

What are the Symptoms?

Most people, including pregnant women, do not have any symptoms.

Some may have mild flu-like illness, swollen glands, or eye symptoms.

How should I reduce the risk of toxoplasmosis during pregnancy?

If you have been tested negative for toxoplasmosis IgG before or during pregnancy, it means that you have no immunity against toxoplasmosis during your current pregnancy. If you have not been tested for toxoplasmosis, it is prudent to assume that you do not have immunity against toxoplasmosis. Then you should do preventive measures to reduce the risk of toxoplasmosis during pregnancy.

Do’s:

- Wash hands with soap and water before and after preparing food and before eating.

- Wash fruit and vegetables thoroughly.

- Cook all meat thoroughly, making sure it is not pink or bloody.

- Wear gloves when gardening and wash hands afterwards.

- Get someone else to change cat litter trays if possible, or use gloves and wash hands well afterward.

Don’ts:

- Eat raw or undercooked meat or cured meats like salami or Parma ham.

- Drink unpasteurized goat’s milk or products made from it.

If you have a cat:

- Avoid handling cat litter if possible.

- Change litter daily (it takes days for cat poo to become infectious), or better still, ask someone else to change the litter daily.

What Are the Risks to the Baby?

If you get infected during pregnancy, your baby may or may not get infected. The risk of your baby getting infected is lowest in the first trimester and highest in the third trimester.

However the risk of damage to the baby is highest if the baby gets infected in the first trimester and lowest if the baby gets infected in the third trimester.

Most babies with toxoplasmosis infection at birth may seem healthy but may develop issues months or years later, including problems with eyes, hearing, or development.

How Is Toxoplasmosis Diagnosed?

A blood test can check if you have had toxoplasmosis recently.

Toxoplasmosis IgM is positive when there is a recent maternal infection, usually in the last 3-4 months. Occasionally, this may persists to be positive for up to 2 years.

Toxoplasmosis IgG is positive when there is a past maternal infection. It, however, does not give a clue about when that infection occurred.

Toxoplasmosis IgG avidity can be performed to date the infection. Toxoplasmosis IgG avidity is low if the infection was in the last 4 months, and toxoplasmosis IgG avidity is high if the infection is more than 4 months ago. For example, if you are 12 weeks pregnant with IgM and IgG positive and then IgG avidity is high, it would exclude toxoplasmosis infection during pregnancy.

However if toxoplasmosis IgM and IgG are positive after 16 weeks (with no prior IgM and IgG testing), a high IgG avidity does not exclude toxoplasmosis during pregnancy. Specialized test like AC/HS sent to specialized laboratory in the US may allow us to further define the timing of the infection.

What happens when you are diagnosed to have toxoplasmosis infection during pregnancy?

If you are diagnosed during pregnancy, medication like spiramycin may be prescribed to reduce the risk or transmission of the parasite from the mother to the fetus.

An amniocentesis would be offered in the late second trimester (usually after 17 weeks or 8 weeks after a known timing of the infection). If amniocentesis shows that the fetus is not infected, we continue with spiramycin to continue to suppress the risk of infection to the fetus. If amniocentesis shows that the fetus is infected, more specific treatment against toxoplasmosis would be offered. Ultrasound scan would be performed to assess if there are structural abnormalities due to the toxoplasmosis. Babies with congenital toxoplasmosis may also be given medicine after birth.