A mother with genital herpes can easily deliver a healthy baby. And most can have a normal vaginal delivery. Less than 0.1 percent of infants born in the United States each year get infected with genital herpes during birth, according to the American Social Health Association.
A mother who was infected with herpes prior to getting pregnant passes herpes antibodies on to her fetus, protecting it from becoming infected with the virus. After birth, as the baby develops its own immune system, it loses these antibodies.
The danger period is late in pregnancy. The greatest chance of delivering a baby infected with herpes occurs in women who first become infected with genital herpes in the last trimester, says Zane Brown, M.D., professor of obstetrics at the University of Washington in Seattle. "The mother doesn't have time to build up antibodies."
For newborns infected with herpes, the consequences are devastating. "More than 40 percent die or have severe brain damage," says Brown.
Brown recommends a cesarean section if the primary infection is in the latter half of the pregnancy, or if the mother with long-standing genital herpes has any symptoms of genital herpes at the time of labor. He also recommends that all expectant mothers get a type-specific blood test for herpes in the first trimester of pregnancy. If negative for both HSV-1 and HSV-2, her partner should be tested. If the partner has herpes, sexual contact that could put the mother at risk of acquiring genital herpes should be avoided in the last trimester of pregnancy.
For several months after birth, infants are at risk for getting herpes. People with oral herpes (cold sores) should avoid kissing the baby. Wearing a mask over the cold sore when around the baby is recommended.
If a baby is infected with herpes, early treatment is critical.