Test Overview

rubella blood test detects
antibodies that are made by the
immune system to help kill the
rubella virus. These antibodies remain in the
bloodstream for years. The presence of certain antibodies means a recent
infection, a past infection, or that you have been vaccinated against the

Rubella (also called German measles or 3-day measles)
usually does not cause long-term problems. But a woman infected with the
rubella virus during pregnancy can transmit the disease to her baby (fetus). And serious birth defects called congenital
rubella syndrome (CRS) could develop, especially during the first
trimester. Birth defects of CRS include cataracts and
other eye problems, hearing impairment, and heart disease.
Miscarriage and stillbirth are also possible
consequences for pregnant women. The vaccination to prevent rubella protects
against these complications.

A rubella test is usually done for a
woman who is or wants to become pregnant to determine whether she is at risk
for rubella. Several laboratory methods can be used to detect rubella
antibodies in the blood. The most commonly used method is the enzyme-linked
immunosorbent assay (ELISA, EIA).

Why It Is Done

A test for
rubella is done to find out if:

  • A woman who is or wants to become pregnant is
    immune to rubella.
  • A recent infection was caused by the rubella
    virus. The presence of IgM antibodies means a current or recent
  • A person has been vaccinated against rubella. The
    presence of IgG antibodies means immunity received through either
    vaccination or a past infection.
  • Health professionals who are in
    contact with pregnant women have had rubella. A health professional who has not
    had rubella may need to be vaccinated to prevent the risk of spreading rubella
    to a pregnant woman.

Some babies born with birth defects may be tested for
congenital rubella.

How To Prepare

No special preparation is required
before having this test.

How It Is Done

The health professional taking a sample
of your blood will:

  • Wrap an elastic band around your upper arm to
    stop the flow of blood. This makes the veins below the band larger so it is
    easier to put a needle into the vein.
  • Clean the needle site with
  • Put the needle into the vein. More than one needle stick
    may be needed.
  • Attach a tube to the needle to fill it with
  • Remove the band from your arm when enough blood is
  • Put a gauze pad or cotton ball over the needle site as
    the needle is removed.
  • Put pressure on the site and then put on a

How It Feels

The blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or


Blood test

There is very little chance of a
problem from having a blood sample taken from a vein.

  • You may get a small bruise at the site. You
    can lower the chance of bruising by keeping pressure on the site for several
  • In rare cases, the vein may become swollen after the
    blood sample is taken. This problem is called phlebitis. A warm compress can be
    used several times a day to treat this.


rubella blood test detects
antibodies that are made by the
immune system to help kill the rubella virus. The test for IgG antibodies is most common and is the test done to see if a woman who is pregnant or planning to get pregnant is immune to rubella.

The normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what’s normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.

Rubella blood testfootnote 1

More than 10 international units per milliliter (IU/mL) IgG antibodies. A positive rubella IgG test result is good-it means that you are immune to rubella and cannot get the infection. This is the most common rubella test done.


Less than 7 IU/mL IgG antibodies and less than 0.9 IgM antibodies. This means you are
not immune to rubella. If you are a woman thinking about getting pregnant,
talk with your doctor about getting a rubella vaccine before pregnancy.

A test for rubella IgM antibodies is done only if the doctor suspects you have a current rubella infection. More than 1.1 IU/mL IgM antibodies means you had a recent rubella infection or you have a current infection.footnote 1

What Affects the Test

There are no factors that would
interfere with the test or the accuracy of the results.

What To Think About

  • If a woman who wants to become pregnant has not
    had rubella, she can receive a shot (vaccination) to help protect her against
    getting the disease. But she must wait 1 month after she gets the shot before
    becoming pregnant to fully protect her baby.
  • A woman should not get
    a rubella shot while she is pregnant, and she should avoid people who have or may have
  • A rubella
    virus culture is not often done because it is a more
    difficult test.
  • Exposure to rubella in the third
    trimester may not be as serious since the baby (fetus) is fully developed. But these babies can have
    the infection and be contagious.
  • If congenital rubella is
    suspected, both the mother and her baby need blood tests.



  1. Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

Other Works Consulted

  • Centers for Disease Control and Prevention (2001). Control and prevention of rubella: Evaluation and management of suspected outbreaks, rubella in pregnant women, and surveillance for congenital rubella syndrome. MMWR, 50(RR-12): 1-23.
  • Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
  • Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.


ByHealthwise Staff
Primary Medical Reviewer John Pope, MD – Pediatrics
E. Gregory Thompson, MD – Internal Medicine
Kathleen Romito, MD – Family Medicine
Specialist Medical Reviewer Christine Hahn, MD – Epidemiology

Current as ofMay 4, 2017