The term TORCH is composed of the first letters of the English names of a variety of microorganisms and viruses that cause intrauterine infections.T is the prefix for Toxoplasma (Toxoplasma); O is other pathogenic microorganisms or viruses, including Chlamydia trachomatis, hepatitis B virus, coxsackievirus, syphilis spirochetes, and HIV; R is rubella.virus; C is cytomegalovirus (Cytomegalo.virus); H is herpes virus (Herpes.virus). According to statistics, there are about 600,000 defective babies born in China every year, of which TORCH infection is one of the important causes of birth defects. As time goes by, TORCH screening is getting more and more attention. The National Health and Family Planning Commission has made TORCH screening a mandatory test for the prevention of birth defects, and the Guidelines for Preconception and Pregnancy Care (1st edition) developed by the Obstetrics and Gynecology Group of the Chinese Medical Association lists TORCH as the preferred preparation item in the first 3 months of pregnancy. 1. Can TORCH screening diagnose birth defects? No. TORCH screening is not a diagnosis of fetal infection, it is a diagnosis of infection in pregnant women. Screening is to screen individuals (infected) at risk for a certain disease (virus) in the population (pregnant women), diagnose the latter (diagnosis of fetal infection), and intervene in patients (fetuses) or disease carriers (pregnant women) for prevention and treatment purposes. 2.What are the common features of TORCH infection? Mother-to-child transmission, fetal risk during early pregnancy and neonatal risk during late pregnancy. Pregnant women are asymptomatic or have very mild symptoms. The virus can cause intrauterine infection through the placenta, which can cause premature birth, miscarriage, stillbirth or malformation, etc. 3.What is the difference in clinical significance of TORCH infection detection indicators? Direct indicators (viral antigen, viral DNA, viral RNA viral culture) detects the virus itself, which is related to the replication pattern, latent location and other characteristics of the virus, and is suitable for diagnosis. 4.How many types of infection are there in pregnancy? Infections during pregnancy are divided into initial (primary) infection, previous infection, recurrent infection, and reinfection, and their concepts should not be confused. Pre-existing infection. Previous infection with the virus, the body has produced antibodies or the virus is dormant and exists in a latent state. Recurrent infection. Intermittent excretion of the virus in the presence of host immune function, a reactivation of latent endogenous virus. Reinfection. Reinfection occurs when an already immunized individual is exposed to a new virus of exogenous origin. It is not possible to distinguish recurrent infection from reinfection by serological methods, but only by viral isolation and molecular biology. Congenital infection. The result of transplacental transmission of the virus. Initial or recurrent infection of the mother can transmit the virus to the fetus, resulting in congenital fetal infection. 5.Why should screening test IgG and IgM be done at the same time? IgG and IgM screening tests should be done at the same time, as IgM alone often gives inappropriate results. positive IgM does not fully prove recent infection, and IgM can be present continuously for several years after infection in some populations, so a positive IgM alone cannot be diagnostic. 6.Why is there no absolute reference value for antibody screening? TORCH virus infection is a dynamic process from mother to fetus, and there is no obvious cut-off point for each time period. For example, a 4-fold increase in IgG is often used as an indicator of recurrence or reinfection. 7.Why is quantitative analysis the best and most advanced choice? The production of IgG or IgM in the body during pregnancy is a rapidly changing process that can only be detected by quantitative analysis of concentration changes. Quantitative analysis helps to detect false-positive or false-negative results. 8, TORCH screening IgM, IgG antibody production significance? The body has a certain degree of immunity, when the body is infected by pathogens, the body will produce the appropriate antibodies (immunoglobulins) to resist the pathogens to protect the normal functioning of the body. The general rule is that IgM antibodies are produced first, followed by IgG antibodies. 9.How to diagnose the initial and recurrent cytomegalovirus infection during pregnancy? Initial infection. The diagnosis of initial maternal cytomegalovirus infection in pregnancy should be based on the new appearance of virus-specific IgG antibodies in the serum of pregnant women (who have previously had a negative serologic response) or the discovery of specific IgM antibodies accompanied by a decrease in IgG antibody affinity. Recurrent infection. Diagnosis should be based on a pregnant woman previously tested positive for IgG antibodies, a significant increase in the current IgG antibody titer (4-fold rise in quantitative testing), with or without the presence of IgM antibodies, and a high affinity for IgG (≤16 weeks); or a positive cytomegalovirus culture from a urine, saliva, or throat swab specimen or other tissue in the body. 10. How is maternal rubella virus infection diagnosed? The determination of rubella virus-specific IgG and IgM by serological methods is a simple, sensitive and accurate method with the following diagnostic criteria. Fourfold increase in rubella virus IgG antibody titers between acute and recovery serum samples. Positive rubella virus-specific IgM antibodies. A positive maternal blood IgM is accompanied by a serologic conversion indicator, i.e., a change from negative to positive IgG. In the case of a positive maternal IgM blood, a 4-fold increase in IgG antibodies in two consecutive sera (between 0.5 and 1 month) may also be observed. It is worth noting that serological tests are best performed within 7-10 d of the appearance of the rash and repeated once after 2-3 weeks. 11.How to distinguish between previous Toxoplasma infection and recent infection? Infectious diseases during pregnancy are one of the most important factors causing stillbirth, fetal malformation and mental retardation in children, the most important of which is TORCH infection in pregnant women. However, for many physicians working in obstetrics and gynecology, the interpretation and management of TORCH screening results is a major problem. The misinterpretation of abnormal results often brings fear to patients and increases their financial burden in repeated examinations, and we hope that the answers to the above questions will enable more health care workers to get out of the misunderstanding.