At what stages is syphilis contagious?

Syphilis is highly contagious during the primary and secondary stages of infection. Individuals in the early part of the latent stage are still contagious, particularly as relapses into the secondary stage occur in around 25% of infected individuals. When relapses no longer occur, a person is not contagious through contact. However, infected pregnant women in the latent stage are still at increased risk of miscarriage, stillbirth, infant death shortly after delivery, and passing syphilis to the baby (congenital syphilis).