Herpes, whether on the mouth or genitals, is caused by a family of over 70 related viruses. These viral infections cause small, fluid-filled blisters to develop on the skin and mucous membranes. There are actually eight different types of herpes simplex viruses that both children and adults can acquire, but two are by far the most common: HSV-1 and HSV-2.
“You don’t want an infant delivered through infected birth canal or vulva because the infant can be infected,” Cullins explains. A neonatal herpes infection is a real risk because it can cause problems with brain development and eye and skin infections, or even be fatal. And since there is more risk for transmission from mother to baby during an initial outbreak than during a recurrent outbreak, the CDC stresses that it’s incredibly important for pregnant women to avoid contracting a new herpes infection.
A 2004 study in the New England Journal of Medicine found that suppressive therapy decreases the risk of HSV-2 transmission from symptomatic, infected partners to uninfected partners by 48%. So “the risk of transmission is significantly reduced, but cannot be eliminated even with suppressive therapy,” Johnston explains, and she stresses that the virus can be passed along even without signs or symptoms.