Neonatal herpes is a herpes infection in a newborn baby. It's caused by the herpes simplex virus, a highly contagious virus that can cause cold sores and genital ulcers in adults.
Herpes can be very serious for a young baby, whose immune system won't have fully developed to fight off the virus.
Thankfully, neonatal herpes is rare in the UK and can be prevented by following some simple advice.
How does a newborn baby catch herpes?
During pregnancy and labour
A newborn baby is at risk of catching herpes if the mother had genital herpes for the first time within the last six weeks of her pregnancy.
There's a risk the mother will have passed the infection on to her baby if she had a vaginal delivery.
This risk is much lower if the mother has had genital herpes before.
Learn more about the risks of genital herpes and pregnancy.
The herpes simplex virus can also be passed on to a newborn baby if:
- a person has a cold sore and kisses the baby
- the mother breastfeeds her baby with herpes sores on her breast – these can develop after touching her cold sore and then her breast
Cold sores are at their most contagious when they burst (rupture). They remain contagious until completely healed.
What are the warning signs in babies?
Because newborn babies have underdeveloped immune systems, they can quickly become seriously ill after catching the virus.
A newborn baby infected with herpes may:
- become lacking in energy (listless) and sleepy
- stop feeding
- be floppy
- have a high temperature (fever) – find out how to take your baby's temperature
- have a high-pitched cry
- have breathing difficulties or start grunting
- breath rapidly
- have a blue tongue and skin (cyanosis)
- have a rash
The baby's health can deteriorate quickly if the virus spreads to their brain or other parts of their body.
What should you do if you think your baby has it?
Contact your GP or midwife as soon as possible if your baby has any of the above symptoms and you're worried. You may be advised to take your baby to your nearest accident and emergency department.
Neonatal herpes is usually treated with antiviral drugs given directly into the baby's vein (intravenously). This treatment may be needed for several weeks. Any related complications, such as fits (seizures), will also need to be treated.
The baby can be breastfed while receiving treatment, unless the mother has herpes sores around her nipples. If the mother is taking antiviral treatment too, this can be excreted in her breast milk but is not thought to cause any harm to the baby.
How serious is herpes for a baby?
Sometimes neonatal herpes will only affect the baby's eyes, mouth or skin. In these cases, most babies will make a complete recovery with antiviral treatment.
However, the condition is much more serious if it has spread to the baby's organs. Nearly a third of infants with this type of neonatal herpes will die, even after they've been treated.
If widespread herpes is not treated immediately, there's a high chance the baby will die.
How can neonatal herpes be prevented?
If you're pregnant and have a history of genital herpes, tell your doctor or midwife. You may need to take medication during the last month of pregnancy to prevent an outbreak of vaginal sores during labour.
Delivery by caesarean section is recommended if the genital herpes has occurred for the first time in the last six weeks of your pregnancy.
If you develop a cold sore or think you're coming down with a herpes infection, take these precautions:
- don't kiss any babies
- wash your hands before contact with a baby
- wash your hands before breastfeeding and cover up any cold sores to avoid accidentally touching your mouth and then breast – this is enough to transfer the virus
Support and advice if you've been affected
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