Fresh episode
The test is useful at the first significant episode (fever, multiple rashes) to confirm the primacy - it is more severe and requires a full course of acyclovir. Isolated IgM+ without clinical evidence is a common laboratory artifact: retake and IgG dynamics bring clarity.
When is it appointed?
- pregnancy planning - TORCH status;
- pregnancy - screening and clarification of doubtful results;
- decision to vaccinate against rubella;
- lymphadenopathy, prolonged low-grade fever - etiology;
- clarification of the stage of infection (avidity).
Reading antibodies correctly
IgM is a marker of a fresh infection (but often “phonitis” is false), IgG is immune memory and protection. For pregnancy, the ideal profile is “IgG+, IgM−” (there is immunity, there is no risk); “IgG−, IgM−” means vulnerability (rubella - vaccination BEFORE conception!); “IgM+” requires clarification by IgG avidity: high avidity = long-standing infection, no danger. A competent interpretation saves you from unnecessary fears and interventions - the clinic doctor will analyze your profile.
