After TORCH infection, patient-specific antibodies IgM and IgG can rise rapidly, with IgM appearing early and lasting 6-12 weeks, while IgG appears late but can be maintained for life. Therefore, we often consider IgG positivity as a previous infection, while IgM positivity is used as a diagnostic indicator of initial infection. On Method/Step IgG positive IgM negative Having been infected with this virus before or having been vaccinated and having developed immunity, it is very unlikely that the fetal baby will be infected; IgG negative IgM negative Indicates that the pregnant woman is susceptible. It is best to repeat the IgG test during pregnancy to observe for a positive switch. IgG-positive IgM-positive indicates that the pregnant woman may have a primary infection or reinfection. This can be identified by IgG affinity test. IgG-negative IgM-positive Recent infection or acute infection; may also be a false positive IgM due to other interfering factors. Need to be rechecked after 2 weeks, if IgG positive, it is an acute infection, otherwise it is judged as false positive.