Congenital syphilis is an infection transmitted from mother to child during pregnancy and/or delivery caused by the bacterium Treponema pallidum. Congenital syphilis can cause severe illness in babies including premature birth, low birth weight, birth defects, blindness, and hearing loss. It can also lead to stillbirth and infant death. Tests and treatment for pregnant women are readily available. Over the last several years, California has experienced a steep increase in syphilis among women and congenital syphilis.