Usually tests to detect possible infections during pregnancy are based on the detection of Ig M (acute phase) and IgG (chronic phase) antibodies for rubella, toxoplasmosis, CMV and herpes simplex.

THERE ARE NUMEROUS DIAGNOSTIC TESTS FOR MATERNAL-FOETAL TRANSMITTED INFECTIONS, as follows:

1. The detection of viral antigens is evidenced by antigene-antibody (with antibodies belonging to immune sera from animal that can be marked enzyme (immunoenzymatic – ELISA tests) or fluorescent (immunofluorescence reaction).

2. Viral genome detection with molecular tests or nucleic acids detection tests (DNA or RNA): PCR, Rt-PCR, Real Time PCR, etc.

3. Serological diagnosis is an indirect diagnosis – does not test the virus but antiviral antibodies produced in response to the entry into the body of a viral antigen (immune response); it is based on all antigen-antibody reactions (most commonly used immunoenzymatic – ELISA, Western Blot, etc.).

Two types of investigations can be carried out:

• Detection of IgM antiviral antibodies (occurring in primary immune response, i.e. on the first meeting with a certain kind of virus); usually is used ELISA test
• It is observed either IgG antiviral antibodies occurring in the secondary immune response (after a period of at least 2-3 weeks from a viral infection) or is determined seroconversion – in sample I – there are no antibodies then, in the sample II specific antibodies of the detected virus appear, or a significant increase in antibody titers between the two samples (at least 4 times) is determined.

4. Tests for virus visualization. Viruses have dimensions below the detection limit of the optical microscope – viral particles can not be seen in the optical microscope; viral particle detection is done  only with electronic microscope, rarely used.

5. It is also possible to use viral isolation for diagnosis, usually for research, being laborious and requiring a highly specialized virology laboratory. Viral isolation produces viral replication in the laboratory, associated with multiplication of virions and characteristic changes in viral infected cells, most commonly using isolation systems called cell cultures.