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Herpes in newborn babies (neonatal herpes)

Neonatal herpes is a herpes infection in a newborn baby. It’s caused by the cold sore virus (herpes simplex).

The herpes virus spreads by direct skin-to-skin contact. It often appears as small blisters filled with fluid. But babies with neonatal herpes do not always get cold sore blisters.

Neonatal herpes can be very serious or even fatal for young babies. Their immune systems have not developed enough to fight the infection. The risk is highest in the first 4 weeks after birth.

What to do if your baby seems unwell

Babies can become unwell quickly. Act fast if you think your baby might have neonatal herpes or if you are worried about them.

Urgent advice: When to call 112 or 999

Call 112 or 999 if your baby:

  • will not wake up (unresponsive)
  • is difficult to wake
  • is having trouble breathing, is breathing fast or is making grunting noises
  • has a blue tongue, lips or skin
  • has a seizure (fit or convulsion)

Talk to your GP urgently if your baby:

  • is not feeding
  • is irritable
  • has a high temperature (over 38 degrees Celsius)
  • has a rash, blisters or sores on their skin, eyes or inside their mouth

Treatment if your baby catches neonatal herpes

Your baby will usually be given antiviral medication if they get neonatal herpes. This is given through a drip into their veins.

Most babies continue to breastfeed while being treated. Talk to your GP if you have blisters on your breast or around your nipples.

For some babies with neonatal herpes, the virus only affects their skin, eyes or mouth. In this situation, most babies make a full recovery after treatment with antiviral medication.

If the virus spreads to a baby's organs, the infection is very dangerous. Around 1 in 3 babies die if this happens. Follow the advice on preventing neonatal herpes.

Preventing neonatal herpes

If you're pregnant and have had genital herpes in the past, tell your GP, obstetrician or midwife.

They may prescribe an antiviral medicine to take in the last month of pregnancy to prevent an outbreak of vaginal sores during labour.

If you get genital herpes during the last 6 weeks of your pregnancy, you might have a caesarean birth.

If you develop a cold sore or think you have a herpes infection:

  • do not kiss your baby
  • wash your hands before contact with your baby
  • cover up any cold sores before breastfeeding to avoid touching your mouth and then your breast

Make sure visitors take the same precautions.

Page last reviewed: 24 April 2021
Next review due: 24 April 2024

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.