TORCH

At a Glance

Why Get Tested?

To detect certain infectious diseases that can cause birth defects in a newborn; sometimes to screen pregnant women for these infections

When To Get Tested?

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

Sample Required?

A blood sample drawn from a vein in the woman's arm by needle or by heelstick for infants

Test Preparation Needed?

None

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Lab Tests Online is an award-winning patient education website offering information on laboratory tests. The content on the site, which has been reviewed by laboratory scientists and other medical professionals, provides general explanations of what results might mean for each test listed on the site, such as what a high or low value might suggest to your healthcare practitioner about your health or medical condition.

The reference ranges for your tests can be found on your laboratory report. They are typically found to the right of your results.

If you do not have your lab report, consult your healthcare provider or the laboratory that performed the test(s) to obtain the reference range.

Laboratory test results are not meaningful by themselves. Their meaning comes from comparison to reference ranges. Reference ranges are the values expected for a healthy person. They are sometimes called "normal" values. By comparing your test results with reference values, you and your healthcare provider can see if any of your test results fall outside the range of expected values. Values that are outside expected ranges can provide clues to help identify possible conditions or diseases.

While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents, and techniques. This is a reason why so few reference ranges are provided on this site. It is important to know that you must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."

For more information, please read the article Reference Ranges and What They Mean.

What is being tested?

TORCH is an acronym for a group of infectious diseases that can cause illness in pregnant women and may cause birth defects in their newborns. The TORCH panel is a group of blood tests that detect the presence of antibodies produced by the immune system in response to these infections. Confirmation of an active infection may require more specific tests.

The following tests make up the TORCH panel: Toxoplasmosis, Rubella, Cytomegalovirus, and Herpes simplex virus.

Toxoplasmosis is a parasitic infection that can be passed from mother to baby through the placenta during pregnancy. An infection with Toxoplasma gondii can cause eye and central nervous system infections as well as brain and muscle cysts. If acquired during the pregnancy, it may result in a miscarriage or cause birth defects, though this depends on the time during the pregnancy when the infection was acquired by the mother. Toxoplasmosis is acquired by ingesting the parasite when handling the stool of infected cats, drinking unpasteurized goat's milk, and, most commonly, by eating contaminated meat.
Rubella is the virus that causes German measles. If contracted early in the pregnancy, an infant may develop heart disease, retarded growth, hearing loss, blood disorders, vision problems, or pneumonia. Problems that may develop during childhood include central nervous system disease, immune disorders, or thyroid disease.
Cytomegalovirus (CMV) is another viral infection that a mother may have acquired. More than half of all American adults have been infected with CMV at some point in their life and, in most cases, it does not cause severe illness. However, it may pass to a baby during the birth process and can also infect newborns through breast milk. Infected infants may have severe problems, such as hearing loss, vision problems, mental retardation, pneumonia, and seizures.
Herpes simplex virus (HSV) is a common viral infection. The two most common infections with HSV are "cold sores" affecting the lips and genital herpes. Both of these infections can recur. HSV is most commonly acquired through oral or genital contact. Newborns who contract the virus usually do so during travel through the birth canal of a woman who has a genital infection with HSV. The virus may spread throughout the newborn's body, attacking vital organs. Treatment with specific antiviral medication should begin as soon as possible in the infected newborn. Even if treated, surviving babies may have permanent damage to their central nervous system.

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.

How is the sample collected for testing?

A blood sample is required for the test. Blood can be collected by a heelstick from an infant or a needle is used to draw blood from a vein in a woman's arm.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

Common Questions

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:

Toxoplasmosis

Rubella

Cytomegalovirus (CMV)

Herpes simplex virus (HSV)

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.
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).
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.
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.
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.

TORCH

How is the sample collected for testing?

Is any test preparation needed to ensure the quality of the sample?

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