Usually hospitalized patients and pregnant mothers are routinely prescribed syphilis tests during pregnancy, RPR negative means no syphilis, if RPR positive, the doctor will prescribe TPPA for further examination, the results of the confirmatory test TPPA is negative, the patient has no syphilis infection? With this question, please look down. Syphilis is a chronic, systemic sexually transmitted disease caused by the syphilis spirochete. In the early stage, it mainly invades the skin and mucous membranes, and in the late stage, it invades the cardiovascular system and the central nervous system. There are 4 ways of transmission: sexual contact, indirect contact, blood transmission, and mother-to-child transmission. The common serologic tests for syphilis in most hospitals are RPR and TPPA. RPR, or Rapid Plasma Reaction, detects antibodies to cardiolipin produced in the patient’s serum instead of antibodies to the syphilis spirochete itself. It is mainly used for syphilis screening and efficacy tracking. TPPA is the syphilis spirochete hemagglutination test, which is a serologic test for syphilis spirochete antigen, detecting the antibody of syphilis spirochete itself. It is a confirmatory test, and a positive result basically confirms the diagnosis. Even if cured, a positive result usually stays, like a “scar” for the rest of your life. As you can see from the chart above, going back to the previous question, a positive RPR and a negative TPPA result means that there is no syphilis infection due to a false positive result caused by a laboratory error or some disease. If both TPPA and RPR are positive, the diagnosis of syphilis is confirmed. Most patients with syphilis have no clinical symptoms and are only found to have syphilis by serologic testing, which is referred to as “hidden syphilis”. Since they do not show clinical symptoms or discomfort, if they are not tested, they will pass on syphilis to their children once they have delayed giving birth, which is called congenital syphilis. Newborns with congenital syphilis may present with various clinical symptoms such as failure to thrive, skin rash, hepatosplenomegaly, and bone lesions. Mother-to-child transmission of syphilis has a 50 to 80 percent likelihood of causing adverse pregnancy outcomes such as miscarriage, stillbirth, preterm labor, low birth weight, and congenital syphilis. Happily, with appropriate treatment, most can give birth to healthy babies. Detection in early pregnancy and prompt and standardized treatment will greatly reduce the risk of the baby being born infected. Penicillin is an effective drug for treating syphilis and prevents more than 98% of congenital syphilis through the placenta. Finally, there is good news for pregnant mothers! Prevention of mother-to-child transmission of HIV, syphilis and hepatitis B is a major public health program for mothers and children in China. We offer free HIV, syphilis and Hepatitis B screening (referred to as AiMeiB) to every pregnant mother in early pregnancy. If syphilis infection is detected during early pregnancy, do not panic, and seek medical treatment with penicillin in a timely manner to stop the possibility of syphilis transmission from mother to child, and then you can conceive and give birth to a normal baby. Follow up with your doctor regularly.