Introduction: Syphilis is a sexually transmitted infection caused by the anaerobic spirochete Treponema pallidum (TP) and has been an important cause of morbidity and mortality for more than 500 years. One third of patients who do not receive treatment will progress to advanced stages of the disease: hence the importance of early diagnosis. Development: Most cases of congenital syphilis result from the transmission of T. pallidum to the fetus during early syphilis, while most complications in pregnancy in treated women occur during the third trimester. This highlights the importance of timely screening and treatment during pregnancy. Regarding treatment, the effectiveness of penicillin in pregnancy and the prevention of congenital syphilis are not discussed. This drug has been used for over half a century, but the discussion centers on the best scheme. In 1972 it was determined from clinical experience and without randomized controlled trials that the treponemicidal dose is one that maintains the minimum concentration of 0.03 international units of penicillin per milliliter (0.018 ?g/mL) for 7 to 10 days without interruption for more than 24 hours. We will discuss the desensitization protocol, the Jarisch-Herxheimer reaction and implications in pregnancy, and the alternative schemes used today. Conclusions: Pregnancy syphilis is still a public health problem in developing countries. In this way, it is essential to provide timely interventions and prenatal care. Prenatal screening has been shown to decrease the rate of maternal-fetal transmission and adverse pregnancy outcomes. Treatment with penicillin G, based on clinical experience and case series, remains the intervention of choice.