What is the Rubella Antibody (IgM) test?

The Rubella Antibody (IgM) test measures IgM antibodies produced by the immune system in response to recent or current rubella virus infection. IgM antibodies typically appear shortly after infection and decline over time.

Unlike IgG, which indicates long-term immunity, IgM is used to assess acute infection. This test is particularly important in pregnancy or when symptoms suggest rubella exposure.

Rubella is usually mild, but infection during pregnancy—especially early pregnancy—can have serious consequences for the fetus.

Why do I need a test for Rubella Antibody (IgM)?

Rubella infection can be difficult to diagnose clinically, as symptoms may be mild or non-specific. IgM testing helps confirm whether recent infection has occurred.

This test is especially important for pregnant individuals or those who have been exposed to rubella and need clarification of infection status.

You may benefit from this test if you:

• Have symptoms suggestive of rubella (rash, fever)

• Have been exposed to someone with confirmed or suspected rubella

• Are pregnant and rubella infection is suspected

• Have unclear rubella immunity with symptoms

• Need confirmation of recent infection

• Require investigation following abnormal antenatal screening

• Have had contact during a rubella outbreak

• Need differentiation between past immunity and acute infection

Benefits of the Rubella Antibody (IgM) test

1. Identifies recent rubella infection
   Detects immune response associated with acute exposure.

2. Critical in pregnancy assessment
   Helps assess fetal risk when infection is suspected.

3. Differentiates acute infection from immunity
   Complements IgG testing for clear interpretation.

4. Supports outbreak investigation
   Useful in public health and exposure settings.

5. Guides clinical follow-up
   Helps determine need for specialist referral.

6. Sensitive marker of early infection
   IgM appears soon after exposure.

7. Non-invasive diagnostic aid
   Requires only a blood sample.

8. Provides clarity when symptoms are mild
   Confirms infection even when presentation is subtle.

Step-by-step – how we offer Rubella Antibody (IgM) testing

Clinic-based testing (UK-wide)

• Choose your nearest UK clinic

• Attend your appointment

• Blood sample collected by a qualified clinician or phlebotomist

• Sample is sent to the laboratory for analysis

At-home or hotel testing (+£60)

• A qualified phlebotomist visits your home or hotel

• Blood sample collected in a comfortable, familiar setting

• No clinic visit or travel required

Both services are available UK-wide.

Your Rubella Antibody (IgM) results explained

Negative IgM

A negative result suggests no evidence of recent rubella infection. This makes current infection unlikely, though timing of exposure should be considered.

Interpretation alongside IgG and clinical context is important.

UK reference interpretation:

• Negative: IgM not detected

Low or borderline IgM

Borderline IgM results may occur very early in infection or due to non-specific immune responses. Repeat or additional testing may be required based on symptoms.

Clinical correlation is essential.

UK reference interpretation:

• Borderline: Low-level IgM detected

Positive IgM

A positive IgM result indicates recent or current rubella infection. This is clinically significant, particularly during pregnancy, and requires prompt medical assessment.

UK reference interpretation:

• Positive: IgM detected