The bacteria can enter the body through the vagina, mouth, or rectum. The bacteria can pass through other openings as well, such as a cut or break in the skin. If syphilis occurs during pregnancy and is not treated, the baby will probably get the disease. The mother's infected blood reaches the baby through the placenta. Some babies infected with syphilis are stillborn or premature.
Many infected babies have no symptoms at birth, but symptoms develop weeks or months later.
Your health care provider will look for chancres on the mother's body surface as well as in the vagina, cervix, and rectum. If sores are found, scrapings from the sores will be examined under a microscope to look for the spiral-shaped bacteria that cause syphilis. Your health care provider may also take a blood sample to look for antibodies to the bacteria in the blood. All women are tested for syphilis at their first prenatal visit. Diagnosis of a newborn with syphilis is based on a history of the mother having syphilis, a physical exam of the baby, blood tests, and possibly x-rays.