A positive result due to a current/recent infection
If further tests show that you have a current or recent infection, it means you are suffering from an acute toxoplasma infection. Further action needs to be taken to assess the risk of passing the infection on to your baby.
If you were infected shortly before conception
Infection caught shortly before conception (within a few weeks before) carries a one percent risk or below of transmission to the baby, but there is a risk of miscarriage if the baby does become infected.
If you were infected in the first trimester (week one to 12)
Infection caught at this stage of pregnancy carries about 10-15 percent risk of transmission to the baby. A baby infected at this stage has a risk of being miscarried or born with severe symptoms such as hydrocephalus (water on the brain), calcifications of the brain, or retinochoroiditis (inflammation of the retina).
If you were infected in the second trimester (week 13 to 28)
Infection caught at this stage of pregnancy brings about 25 percent risk of transmission. A baby infected at this stage is less likely to be miscarried, but is still at risk of developing severe symptoms as above.
If you were infected in the third trimester (week 29 to 40)
Risk of transmitting the infection rises again if toxoplasmosis is caught at this stage of pregnancy, and may be as high as 70–80 percent. Most babies infected will be apparently healthy at birth, but a large proportion will develop symptoms later in life, usually eye damage.
Finding out if the baby has been infected
Further tests can be carried out to find out whether or not the baby is infected, although the tests will not show how severe the damage is. An obstetrician or GP can explain the risks and benefits of conducting these tests. Amniocentesis is a technique where amniotic fluid is removed by a fine needle from the amniotic sac – the fluid-filled sac around the baby. Cordocentesis is a technique where a sample of the baby’s blood is removed from the umbilical cord. These procedures carry a point five to one percent risk of causing miscarriage. They would only be carried out for toxoplasmosis if a recent or current infection in pregnancy had been diagnosed by a previous blood test on the mother. They are normally carried out after 15 weeks of pregnancy. The amniotic fluid or blood from the umbilical cord is then tested at the Toxoplasma Reference Laboratory using a range of specialised tests, which may include:
- looking for antibodies to toxoplasmosis
- a test to look for the parasite’s DNA (molecular testing/PCR).
If this is positive, the baby will be considered to be infected. Results typically take two to five days.A detailed ultrasound scan will show if there is major damage, such as hydrocephalus (water on the brain), but a scan that shows no damage, while reassuring, does not rule out the possibility that the baby is both infected and affected.
A blood sample taken every few months, up to the age of one year, can show whether your baby’s antibody level is falling. By that age, the level should be completely negative. This means that your baby will have lost the antibodies acquired from you and is not infected. When your baby’s blood sample is completely antibody-negative, it means they are definitely not congenitally infected. A falling antibody level is a good sign, but is not conclusive and tests should continue until the antibody level is completely negative.
Breastfeeding and toxoplasmosis
Transmission of the Toxoplasma organism by breastfeeding has not been adequately demonstrated or documented as yet. Because of this and the added advantage of passing on extra antibodies to your baby through your breastmilk, breastfeeding would be especially beneficial in fighting infection and is therefore recommended. pakistan and other government policy on toxoplasmosis screening The pakistan and other government policy Screening Committee recently reported that screening for toxoplasmosis in pregnancy should not be offered routinely as there is not enough evidence that it would help.The Committee suggests that getting pregnant women to avoid undercooked or cured meat and communicating the best ways of avoiding infection is a better way of controlling toxoplasmosis than antenatal screening.