TORCH Screen
Alternate Names : Screening for TORCH Infections
TORCH is an acronym for a special group of infections. These may be acquired by a woman during pregnancy. "TORCH" stands for the following infections:
toxoplasma infection, also called toxoplasmosis
other infections, such as hepatitis B, syphilis, and herpes zoster, the virus that causes chickenpox
rubella, the virus that causes German measles
cytomegalovirus, or CMV
herpes simplex virus, the cause of genital herpes
Children, men, and non-pregnant women can also catch these infections. However, the TORCH infections are mainly important because they can be transmitted to the fetus while it is in the womb. If a mother is exposed to these infections during the first 5 months of pregnancy, serious fetal complications may occur. These include:
miscarriage
congenital heart disease, or heart defects that are present when the child is born
cataract, or a clouding of the lens of the eye
blindness, or significant vision change
hearing impairment, including deafness
small head size, also called microcephaly
mental retardation or other learning, behavioral, or emotional problems
low blood counts, also called anemia
liver or spleen enlargement
pneumonia
Who is a candidate for the test?
Any pregnant woman who has been exposed to the above infections may be a candidate for screening. A pregnant woman who believes she has been exposed should speak with her healthcare provider right away.
How is the test performed?
A small amount of blood is withdrawn from a vein in the arm. This blood is sent to the lab for testing. A blood test called an antibody titer is used to detect antibodies to any the suspected TORCH organism.
An antibody is a special protein made by the immune system that helps fight infections. The body makes specific antibodies in response to specific infections. These antibodies are made in large amounts when an infection occurs. When the initial sample of blood is taken shortly after exposure, the body may not have had enough time to start making antibodies yet. However, a woman can have antibodies to the infection in her blood because of an old infection or from a vaccine.
A second sample of blood is usually taken 10 to 21 days later to see if blood antibody levels or titers against the infection are rising. This generally means that a new infection, instead of an old one, is present. If an old infection is the cause of antibodies in the blood, the level of antibodies will not rise with the second blood sample, as it does with a new infection. This is important, because old infections usually do not result in harm to the fetus, except in the case of herpes. Only infections that are newly caught during the early part of pregnancy usually put the fetus at risk.
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