Congenital syphilis, infection with the spirochete Treponema pallidum, is acquired by the fetus, in utero, from an infected birth parent. This is termed early congenital syphilis when symptoms occur before the age of 2 years. Half of patients are asymptomatic at birth. Early congenital syphilis is characterized by a variable number of cutaneous and extracutaneous findings. Historically, infected infants were said to develop a form of rhinitis, snuffles, that is characterized by excessive blood stained nasal drainage by the infant's third week of life. Snuffles do not seem to occur with as much frequency as previously thought. Other findings include hepatomegaly, splenomegaly, lymphadenopathy, mucous patches, hemolytic anemia, thrombocytopenia, periostitis, and intrauterine growth retardation.

If syphilis remains latent and the infant does not exhibit symptoms until after 2 years of age, the course of the disease is different (late congenital syphilis). Findings include tissue malformation at critical growth periods, incisor teeth abnormalities (called Hutchinson teeth), corneal opacities, and eighth nerve hearing impairment or deafness.

The US Centers for Disease Control and Prevention (CDC) reports that the rate of reported congenital syphilis in the United States has increased dramatically since 2012. The 2019 national rate of 48.5 cases per 100 000 live births represents a 41% increase relative to 2018 (34.3 cases per 100 000 live births) and a 477% increase relative to 2012 (8.4 cases per 100 000 live births). During 2015–2019, the rate of congenital syphilis increased 291.1%.