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
also infected.
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
antibodies because:1
- Collecting amniotic fluid through
amniocentesis 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
intellectual disability, earlier test results are
important to parents who are considering ending such a pregnancy.
In rare cases, PCR produces
false-positive or
false-negative test results. Follow-up testing and
fetal ultrasound monitoring for
hydrocephalus 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.
References
Citations
- Davies JK, Gibbs RS (2008). Toxoplasmosis section of
Obstetric and perinatal infections. In RS Gibbs et al., eds., Danforth's Obstetrics and Gynecology, 10th ed., pp. 346–350.
Philadelphia: Lippincott Williams and Wilkins.
Credits
| By | Healthwise Staff |
|---|
| Primary Medical Reviewer | Sarah Marshall, MD - Family Medicine |
|---|
| Specialist Medical Reviewer | Kirtly Jones, MD - Obstetrics and Gynecology |
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| Last Revised | June 2, 2011 |
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Last Revised:
June 2, 2011
Davies JK, Gibbs RS (2008). Toxoplasmosis section of
Obstetric and perinatal infections. In RS Gibbs et al., eds., Danforth's Obstetrics and Gynecology, 10th ed., pp. 346–350.
Philadelphia: Lippincott Williams and Wilkins.
