Causes of Genital Herpes
Genital herpes can only be contracted through direct sexual contact, including genital-to-genital, mouth-to-genital, or hand-to-genital contact with an infected partner. Individuals cannot contract the virus through kissing. Occasionally, oral-genital contact can spread oral herpes to the genitals (and vice versa). Individuals with active herpes lesions on or around their mouths or on their genitals should only engage in oral sex if they use a condom or place a small piece of latex, called a dental dam, over the vagina or anus.
The chance of a pregnant woman passing herpes to her baby is highest if the first infection occurs near the time of delivery. The virus can be transmitted to the fetus through the placenta during pregnancy or during vaginal childbirth. First-time infection during pregnancy leads to an increased risk of miscarriage, decreased fetal growth, and preterm labor. About 30-50% of infants who are born vaginally to a mother with first-time infection become infected with the herpes virus. Of babies born to women experiencing recurrent outbreaks at the time of birth, one to four percent become infected with the herpes-simplex virus.