Toxoplasmosis Test for Fetus - Topic Overview
When a pregnant woman has
toxoplasmosis, a PCR test on
amniotic fluid is used to learn whether her fetus is
Polymerase chain reaction (PCR) is a method of duplicating
DNA 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
- Collecting amniotic fluid through
amniocentesis is considered safer than fetal blood
- PCR is better than antibody testing to detect
- 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
intellectual disability, earlier test results are
important to parents who are considering ending such a pregnancy.
In rare cases, PCR produces
false-negative test results. Follow-up testing and
fetal ultrasound monitoring for
hydrocephalus can help confirm PCR test
PCR is seldom used to diagnose toxoplasmosis in adults.
Antibody testing of a blood sample is easier and more widely available.