Rubeo Test: test that detects rubella antibodies. Rubella in pregnancy can be dangerous: when to get tested and how to read the results
The rubeo test is a test that is carried out during pregnancy in search of rubella antibodies in maternal blood. This is an important test because it serves to establish whether the expectant mother has already contracted rubella previously, often in childhood, and therefore has antibodies in her body for this disease which, if contracted in pregnancy it can be very dangerous. So let’s see when the rubeo test is performed and how the laboratory results are interpreted.
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Rubella in pregnancy
Rubella is a virus that causes an infection that is usually mild and characterized by fever and rashes lasting about 2-3 days. The infection is highly contagious but is preventable with a vaccine. A rubella test detects and measures rubella antibodies in the blood produced by the body’s immune system in response to rubella virus immunization or infection.
Most people have contracted rubella in childhood, but it is important to make sure that you have already had the disease and, consequently, that you have developed antibodies, because if contracted during pregnancy, rubella is a very dangerous disease, especially in the first trimester, and may increase the risk of intrauterine death, fetal malformation, miscarriage.
Congenital rubella syndrome
The developing baby, especially in the first months of gestation, is more vulnerable to the rubella virus which can be passed from mother to baby while still in the womb. In addition to increasing the risk of miscarriage, the rubella in pregnancy can cause a permanent set of conditions in the newborn baby known as syndrome congenital rubella: it is a group of defects which include:
- intellectual and developmental disabilities,
- clouding of the lens of the eye (cataract),
- liver problems,
- heart defects.
Precisely to protect the fetus from rubella, women who do not have rubella antibodies are advised to undergo the vaccine that we have available, which is effective and safe even in pregnancy.
When taking the Rubeo test
The Rubeo test is performed with a simple blood sample and the sample is analyzed in the laboratory.
The Rubeo Test should be done before or at the beginning of a pregnancy to check immunity, but also in the following cases:
- when a pregnant woman has symptoms of rubella, such as fever and rash;
- when a newborn shows developmental problems or birth defects which may be caused by an infection in the uterus;
- whenever you need to check for a recent rubella infection or check maternal immunity.
If the test is negative, it must be repeated every month until the end of gestation, in case of positive result the risk of intrauterine mortality and fetal malformation, especially if the virus is contracted in the first trimester, is very high.
As explained by the Istituto Superiore di Sanità, all women of childbearing age should be aware of their immune status against rubella and be vaccinated before a possible pregnancy. If a woman is planning to become pregnant, she will have to wait one month after the rubella vaccination.
How to read the exam results
As we said, the rubeo test looks for some specific IgG antibodies, which indicate that the body has already fought the infection in the past, and also for IgM antibodies, which are instead detected when the virus has been recently contracted. The results can be:
- IgG and IgM negative: the test is negative and this means that the woman has never had rubella, therefore vaccination is recommended;
- IgG positive and IgM negative: the woman has been infected with the rubella virus in the past, so she is immune;
- IgG negative and IgM positive: the woman has recently contracted rubella and therefore the situation must be monitored regularly;
- Positive IgG and IgM: the infection is ongoing and action must be taken quickly and effectively to prevent fetal contagion.