Syphilis is a sexually acquired infection caused by a bacteria-like spirochete Treponema pallidum.
Syphilis can be transmitted between partners during sexual intercourse and from an infected pregnant woman across the placenta to a developing baby.
Infection during pregnancy usually results in miscarriage, stillbirth or a congenitally infected baby. Maternal infection is detectable and treatable which prevents transmission to the baby.
Syphilis can be treated with antibiotics.
For symptoms and general information on syphilis, visit NHS Choices.