Herpes and your baby

Herpes is an infection caused by a virus. If you have genital herpes, you can pass the infection to your baby during pregnancy, labor or birth. Genital herpes is sexually transmitted disease (also called STD). Some babies also get herpes from others after birth. If not treated, herpes can cause serious health problems in babies, including deadly infection. Herpes affects about 1 in 3,500 (less than 1 percent) babies in the United States each year.

How do babies get herpes? 

Herpes in babies is caused by two viruses called herpes simplex viruses (also called HSVs):

  1. HSV-1. This virus usually causes cold sores and fever blisters on the mouth and lips. The virus spreads from the mouth to the skin. 
  2. HSV-2. This virus causes most cases of genital herpes. It spreads through sex and skin-to-skin contact. HSV-2 is the most common cause of herpes infection in newborns, but HSV-1 also can cause it. 

Babies can get herpes in three ways: 

  1. Before birth (also called intrauterine herpes). You pass the virus to your baby in the uterus (also called the womb). This kind of herpes is rare.
  2. During labor and birth (also called birth-acquired herpes). This usually happens when a baby passes through an infected vagina (also called birth canal). It’s the most common way babies get infected with the herpes. A baby can get infected without passing through the vagina, but this is rare. It can happen if the amniotic sac breaks before birth. This is the sac (also called bag of waters) inside the uterus that holds your baby. It’s filled with amniotic fluid.
  3. After birth. You or another person can pass the virus to your baby after birth. For example, if you have a herpes sore on your lip and you kiss your baby’s skin, you can pass the virus to her. 

How do you know if your baby has herpes?

Tell your baby’s health care provider if your baby has any of these signs or symptoms:

  • Bleeding easily
  • Small red sores or blisters on the skin, around the eyes or mouth
  • Fast breathing, short periods without breathing or your baby’s skin looks blue 
  • Fatigue, feeling very tired or exhausted
  • Jaundice, when your baby’s skin and the white parts of his eyes look yellow
  • Poor feeding
  • Seizures

To diagnose herpes, your baby’s provider may use these medical tests:

  • Physical exam to look for sores
  • Blood tests
  • Liver function tests
  • Magnetic resonance imaging (also called MRI). MRI is a medical test that makes a detailed picture of the inside of your body. Your baby may need an MRI of the head.
  • Spinal tap, to check spinal fluid for infection
  • Swab of fluid and skin cells from the sores

How can herpes affect your baby’s health? 

If your baby has herpes that isn't treated, he can go into shock. This means organs in his body don’t get enough blood flow. If not treated, shock can cause a baby to go into a coma and die. 

Herpes viruses also can cause a number of health problems in newborns, including: 

Brain infection (also called herpes encephalitis). If the herpes infection spreads to the brain, it can be deadly. Even with treatment, some of these babies die. About 7 in 10 (70 percent) babies develop lasting disabilities, including:

  • Cerebral palsy (also called CP). This is a group of conditions that affects the parts of your brain that control your muscles. It causes problems with movement, posture and balance.
  • Intellectual disabilities. These are problems with how the brain works that can cause a person to have trouble or delays in physical development, learning, communicating, taking care of himself or getting along with others.
  • Seizures
  • Vision and hearing loss

Eye disease, like chorioretinitis. This is inflammation of the retina. The retina is the nerve tissue that lines the back of the eye. This can happen if your baby has intrauterine herpes. 

Multiple organ infection. This is when the herpes infection spreads to and affects several internal organs, like the liver, lungs and kidneys. About 3 in 10 (30 percent) of babies with these widespread infections die. 

Skin, eye and mouth infection. Small, fluid-filled blisters can appear on the skin and around the eyes and mouth. The blisters burst, crust over and finally heal, often leaving a mild scar. With early treatment, most babies develop normally. A small number of these babies have lasting damage to their eyes or nerves. 

How are newborns with herpes infection treated?

Acyclovir (also called Zovirax® Injection or acycloguanosine) is an antiviral medicine used to treat herpes infections in babies. Early treatment with acyclovir can stop the spread of the infection to the brain and other organs. Your baby may need to take acyclovir for several weeks. 

If your baby has serious herpes complications, like shock or seizures, she may need treatment in a hospital. 

How can you keep your baby safe from herpes?

To help keep your baby safe from herpes: 

  • Tell your health care provider you have genital herpes. Your provider checks you for signs of infection during pregnancy and may treat you with acyclovir to prevent an outbreak around the time you give birth. You may need to have a cesarean birth (also called c-section) to help prevent you from passing the herpes virus to your baby. A c-section is surgery in which your baby is born through a cut that your doctor makes in your belly and uterus. 
  • If you have a herpes sore, keep you baby away from it. Don’t kiss your baby when you have a cold sore. If you have a herpes sore on your breast nipple or areola (the dark area around the nipple), stop breastfeeding on that breast. Use a breast pump or manual expression to remove milk from the infected breast until the sore heals. Don’t feed your baby pumped or manually expressed breast milk from the infected breast. Manual expression is when you massage your breasts with your hands to release breast milk. Pumping and manual expression can help keep up your milk supply and prevent your breast from getting engorged, when your breasts become swollen and full of milk. 

See also: Genital herpes and pregnancy

Last reviewed: August, 2014