To detect certain infectious diseases that can cause birth defects in a newborn; sometimes to screen pregnant women for these infections
TORCH
When a baby is born with congenital abnormalities that may be caused by an infection with one of the diseases included in the panel; sometimes if a woman is exposed to certain infections or becomes ill while pregnant
A blood sample drawn from a vein in the woman's arm by needle or by heelstick for infants
None
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How is it used?
The TORCH panel is a group of tests used to screen newborns and, sometimes, pregnant women for certain infections that can cause birth defects in a baby if the mother contracts them during the pregnancy. The tests detect antibodies produced by the immune system when exposed to the infectious diseases.
Some of the antibody tests are ordered individually; the complete TORCH panel is less commonly ordered since more specific and sensitive tests to detect these infections are available.
The blood tests that make up the panel are for:
For more about these infections, see the "What is being tested?" section or click on the links in the bulleted list above to go to the individual test pages.
Other infections that may be tested for at the same time include syphilis, hepatitis B, human immunodeficiency virus (HIV), enterovirus, Epstein-Barr virus, varicella-zoster virus, and parvovirus B19.
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When is it ordered?
The TORCH panel may be ordered when an infant shows any signs or symptoms suggestive of the infections included in the panel, such as:
- Exceptionally small size relative to the gestational age
- Deafness
- Developmental delays
- Seizures
- Heart defects
- Cataracts
- Enlarged liver or spleen
- Low platelet level
- Jaundice
This panel may sometimes be order prior to a woman becoming pregnant or very early in her pregnancy (first trimester).
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What does the test result mean?
Results are usually reported as positive or negative, indicating the presence or absence of antibodies for each of the infections tested for with the panel.
A "normal" result is negative (undetectable) antibody in the blood and means that it is unlikely that the person tested has the infection. However, if a healthcare practitioner strongly suspects that a newborn or pregnant woman has one of these infections, even though the results were negative, other tests for the suspected infection should be done.
A positive result indicates high likelihood of infection with that microbe. However, further testing must be done to confirm these results. Any positive antibody results should be confirmed with additional specific tests before the diagnosis is considered valid.
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Is there anything else I should know?
Use of the TORCH panel to diagnose these infections is becoming less common since more specific and sensitive tests to detect infection are available. Relying on the presence of antibodies may delay the diagnosis since it takes days to weeks for the antibodies to be produced.
Detection of the antigen or growing the microorganism in culture can be done earlier in the infectious disease process and are more specific.
Some recent studies have found questionable benefit to routine TORCH screening in newborns with certain symptoms, such as being small for gestational age, and greater benefit to using more specific methods, such as, in this example, CMV culture.
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What type of testing is used to confirm infection with these microorganisms?
To make the diagnosis of an active infection with one of the TORCH pathogens, more specific confirmatory tests may be required. In a baby, cerebrospinal fluid testing (requiring a lumbar puncture or "spinal tap") is often used to confirm toxoplasmosis, herpes and rubella; urine may be cultured for cytomegalovirus; and skin lesions may be scraped and cultured for herpes simplex virus. Making the diagnosis of toxoplasmosis in the pregnant woman or the baby may require additional blood samples, which are sent to a reference lab that specializes in this testing.