After syphilis is cured, screening for syphilis should be done in the first 3 months of pregnancy, with blocking treatment if positive, or in subsequent pregnancies if negative. Syphilis can be transmitted from a pregnant woman to her fetus through the placenta, through the birth canal when the newborn passes through during labor and delivery, and through breastfeeding contact with contaminated clothing, causing syphilis. Although syphilis is cured, it can come back, so even if it is cured, pregnant women need to be screened for syphilis during the first trimester of pregnancy, and if they are diagnosed as positive, they should be treated with blocking therapy. If negative, screening should be repeated in late pregnancy and before labor, and also in cases of stillbirth after 20 weeks of gestation. It is recommended to observe the fetus for signs of congenital syphilis such as enlarged liver and spleen, abdominal effusion, and fetal growth restriction during ultrasound examination.