TORCH is an acronym for a group of pathogenic microorganisms and is used in clinical practice for routine pregnancy screening and preconception testing of women of childbearing age who are planning to conceive. The aim is to detect the presence of one or more of the pathogenic microorganisms of TORCH and to determine their infection status, as an important measure to avoid adverse pregnancy outcomes. When a woman’s immune response is weakened after conception compared to pre-pregnancy, her resistance to pathogenic microbial infections is reduced, which can easily lead to infection by some pathogens. These pathogenic microorganisms may cause adverse pregnancy outcomes such as miscarriage, stillbirth, congenital malformation of the fetus or various organ lesions through the placenta or birth canal for pregnant women. In case of “new” infections, the impact on pregnancy outcome is much more serious than in case of “re-emerging” infections, especially in early pregnancy, which is more dangerous for the fetus. The most common and potentially most serious consequences are TOX, RV and CMV infections. For example, TOX can lead to fetal hydrocephalus, microcephaly, anencephaly, retinal chorioretinitis (even blindness), hepatosplenomegaly, polycystic kidney, adrenal agenesis, and other adverse pregnancy outcomes. Congenital CMV infection can cause fetal microcephaly, cataract, retinitis, deafness, bile duct malformation, and mental retardation. Congenital rubella syndrome (CRS) often includes congenital cardiovascular disease, ocular defects (such as cataracts, retinopathy, glaucoma, microphthalmia), deafness, and serious lesions of the central nervous system or genitourinary system. The vast majority of these birth defects are untreatable and irreversible. 1, specific IgM antibodies: IgM is the earliest antibody that appears after the infection of a pathogenic microorganism, usually appears in 3-5 d of infection and can last for 3-6 months. IgM (+) of a pathogenic microorganism represents an acute active infection with the corresponding pathogenic microorganism in the near future, and false positives must be excluded clinically. As the infection progresses, the specific IgM antibody titer will gradually decrease in the majority of infected patients until it disappears, and IgM(+) will change to IgM(-). 2. Specific IgG antibodies: IgG appears about 1 week after infection and its titer gradually increases and can last for several years or a lifetime. IgG(+) of a pathogenic microorganism generally indicates a previous infection of the corresponding pathogen, if the IgG changes from (-) to IgG(+) and the titer is increasing, it indicates a “new” infection. In the TORCH test, there are 4 different combinations of IgG and IgM specific to each pathogenic organism that can roughly indicate different infection states. There are 2 possibilities: (1) previous infections, this time “re-emerging”; (2) recent “new” infections, where IgG is present and IgM has not yet disappeared. If TORCH infection is a “new” infection, the risk of congenital infection in the fetus is much higher than that of a “re-emerging” infection. Some studies have reported that the average rate of congenital infection due to “new” CMV infection in pregnant women is about 30-40%, while the rate of congenital infection due to “re-occurring” infection is less than 1.0%. Therefore, based on the above screening results, if the initial diagnosis of recent infection is made, especially if both IgG and IgM are (+), it is necessary to distinguish early whether the infection is “new” or “re-emerging” because it is necessary to wait for a period of time for more than one or two follow-up examinations. This will increase the anxiety of the infected pregnant woman and delay the correct diagnosis and management. Pre-conception screening and counseling should be done at least 3-6 months before conception to allow sufficient time to take some feasible preventive measures, to choose the right time for conception, and to do a good job in pre-conception and pregnancy care for a successful and ideal pregnancy outcome.