Oral herpes, which may show up as cold sores or fever blisters on or near your mouth or sores inside your mouth, is almost always caused by herpes simplex virus type 1 (HSV-1). It's spread by direct contact with the sores, often by kissing.
Herpes simplex virus type 2 (HSV-2) most commonly causes genital herpes, which may show up as blisters or sores on your genitals. If you've never had genital herpes, you're considered susceptible and can contract the virus if you have sex with a contagious partner.
You can also get genital herpes if your partner has oral herpes and performs oral sex on you. Up to a third of cases of genital herpes are caused by the type 1 virus transmitted through oral sex, and this number appears to be increasing.
Once you contract the virus, it settles in a bundle of nerves near your spine forever and may surface again at any time. Some herpes carriers have outbreaks frequently, others only rarely.
You may or may not notice any symptoms during a recurrence, so you may not know when you're having one. This is a problem because you "shed the virus" at these times, which means you're contagious and can infect your partner if you have sex or infect your baby during labor and birth.
Herpes can be treated but not cured. Let your caregiver know at your first prenatal visit if you think you or your partner has ever had a herpes outbreak.
Symptoms, if they occur at all, can vary a lot from person to person. They're likely to be most severe in a primary infection — that is, when you first contract genital herpes and have no oral or genital herpes antibodies to help fight the virus.
Between two and 14 days after exposure to the virus, you may get red bumps on your vagina or vulva, which will turn into blisters and eventually rupture and become painful sores. There may be just a few or you might have a large cluster, and they can last for up to three weeks with a primary infection.
You may have an itchy, burning, painful, or tingling sensation in your genital area, have vaginal discharge, have tender swollen lymph nodes near the groin, and experience some pain when you urinate.
With a primary infection, you might also have flu-like symptoms, including fever, headache, and muscle aches. Some pregnant women get very sick during a primary infection and need to be treated intravenously with an antiviral medication called acyclovir.