Toxoplasmosis Test for Fetus

When a pregnant woman has Reference toxoplasmosis Opens New Window, a PCR test on Reference amniotic fluid Opens New Window is used to learn whether her fetus is also infected.

Polymerase chain reaction (PCR) is a method of duplicating Reference DNA Opens New Window strands from a tiny sample of blood, hair, or tissue. PCR is used to identify infectious diseases, genetic conditions, and genetic links between people.

PCR is preferred over a fetal blood test for Reference antibodies Opens New Window because:^{Reference 1}

• Collecting amniotic fluid through Reference amniocentesis Opens New Window is considered safer than fetal blood sampling.
• PCR is better than antibody testing to detect toxoplasmosis.
• PCR can be done earlier in a pregnancy than a blood test for antibodies. Because first- and second-trimester fetal infection carry the highest risk of birth defects and Reference intellectual disability Opens New Window, earlier test results are important to parents who are considering ending such a pregnancy.

In rare cases, PCR produces Reference false-positive Opens New Window or Reference false-negative Opens New Window test results. Follow-up testing and Reference fetal ultrasound Opens New Window monitoring for Reference hydrocephalus Opens New Window can help confirm PCR test results.

PCR is seldom used to diagnose toxoplasmosis in adults. Antibody testing of a blood sample is easier and more widely available.

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