TPPA is a test for gelatin particle agglutination of syphilis spirochetes. A child born with a positive TPPA test is not necessarily positive, but depends on whether or not transmission of syphilis spirochetes occurs through the placenta during the fetal period, and is also closely related to control of the physical condition. A well controlled pregnancy that does not cause infection may be negative; a pregnant woman with a high level of the pathogen that is not blocked in time and causes transmission may be positive. A positive TPPA is only indicative of a previous infection with the appropriate pathogen. Combined with a syphilis titer of less than 1:4 and prompt interruption of treatment without infection, the child may be negative after birth. If the TPPA is positive and the syphilis titer is significantly high, and if the syphilis is not controlled in a timely manner, it may lead to vertical transmission from mother to child, and the fetus may be positive after birth. Pregnant women with syphilis should be followed up regularly and the level of syphilis in the body should be closely monitored to prevent fetal infection.