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 (First Edition) developed by the Obstetrics and Gynecology Group of the Chinese Medical Association listed TORCH as the preferred preparation for screening in the first 3 months of pregnancy (2011). Question 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 high risk for a certain disease (virus) in the population (pregnant women), diagnose the latter (diagnosis of fetal infection), and intervene with patients (fetuses) or disease carriers (pregnant women) for prevention and treatment purposes. Question 2: What are the common features of TORCH infections? 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 and can cause premature birth, miscarriage, stillbirth or malformation. Question 3: What is the difference in the clinical significance of the indicators tested for TORCH infection? The direct indicators (viral antigen, viral DNA, viral RNA viral culture) detect the virus itself, which is related to the replication pattern, latent location and other characteristics of the virus, and is suitable for diagnosis. Question 4: How many types of infection are there in pregnancy? Infections during pregnancy are divided into initial (primary) infections, previous infections, recurrent infections, and reinfections, the concepts of which should not be confused. 1. Previous infection. The virus has been infected before and the body has produced antibodies or the virus is dormant and exists in a latent state. 2, recurrent infection. Intermittent excretion of the virus in the presence of host immune function, a latent endogenous virus reactivation. 3, reinfection. Reinfection occurs when an individual who has been immunized is exposed to an exogenous new virus. Recurrent infection and reinfection cannot be distinguished by serological methods at present, but only by viral isolation and molecular biological methods. 4. 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 infection of the fetus. Question 5: Why should screening test IgG and IgM be done at the same time? Screening tests for IgG and IgM should be done at the same time, as IgM alone often gives inappropriate results. positive IgM is not sufficient proof of recent infection, and in some populations IgM can be present for several years after infection, so a positive IgM alone is not diagnostic. Question 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 clear cut-off point for each time period, IgG/IgM concentration cut-off is an indicator of infection, but it has limitations, individual concentration gradient changes are more clinically meaningful, for example, when IgG increases 4-fold is often used as an indicator of virus recurrence or reinfection. For example, a 4-fold increase in IgG is often used as an indicator of recurrence or reinfection. Question 7: Why is quantitative analysis an advance and the best choice? The production of IgG or IgM in the body during the initial infection or recurrent infection 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. Question 8: What is the significance of TORCH screening for IgM and IgG antibody production? The body has certain immunity, when the body is infected by pathogens, the body will produce the appropriate antibodies (immunoglobulins) to resist the pathogens in order to protect the normal functioning of the body. The general rule is that IgM antibodies are produced first, followed by IgG antibodies. Question 9: How to diagnose initial and recurrent cytomegalovirus infection during pregnancy? 1. 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 finding of specific IgM antibodies accompanied by a decrease in IgG antibody affinity. 2. Recurrent infection. The 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 urine, saliva or throat swab specimens or other tissues of the body. Question 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, a 4-fold increase in IgG antibodies in two consecutive sera (between 0.5 and 1 month) is also observed. It is important to note that serologic testing is best done within 7 to 10 d of rash appearance and repeated once after 2 to 3 weeks. Question 11: How to distinguish between management of previous and recent Toxoplasma infection? Infectious diseases during pregnancy are one of the most important factors causing stillbirths, fetal malformations 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.