Genital herpes, pregnancy and childbirth
Getting pregnant when you have genital herpes
Having genital herpes does not affect fertility or the ability to get pregnant. Talk to your doctor about taking antiviral tablets if you need to prevent outbreaks when you want to conceive. This is safe.
Genital herpes and early pregnancy – first and second trimester
Having a primary infection of genital herpes (catching herpes in early pregnancy) at this time will not affect the baby or cause a miscarriage. We now know there is no evidence for herpes causing a miscarriage if the mother caught genital herpes in the first three months – although we used to think that there was an increased risk. Catching herpes will not cause miscarriage.
Having outbreaks during pregnancy is normal. These will not harm the baby. Some women have more outbreaks during pregnancy. You may choose to take aciclovir 400 mg three times daily from 36th week of pregnancy to ensure you don’t have an outbreak at term.
Childbirth with genital herpes – you can have a normal delivery with genital herpes
If you have caught genital herpes before becoming pregnant you can give birth normally. This is stated in the 2014 Guidelines for herpes simplex and childbirth from the Royal College of Obstetrics and Gynaecology together with the British Association for Sexual Health and HIV. [And you can see the patient-friendly version here.]
If you wish, you can take aciclovir 400 mg three times daily from 36 weeks on, to ensure you don’t have an outbreak during the birth.
Why is is OK to have a normal delivery even when there is an outbreak of herpes?
Towards the end of pregnancy, babies in the womb receive antibodies to all the infections that their mothers have previously caught. These antibodies protect the baby from catching these viruses during childbirth and afterwards, longer when the mother breast feeds. After that, this protection fades away.
Common sense tells us: since humans began, women with cold sores have kissed their new babies – repeatedly. No one worries that their babies will catch herpes and be affected. The baby of a woman with a genital infection might briefly touch the ‘cold sore’ on her genitals on its way into the world – once. See ‘Neonatal herpes’ in the section below for when babies can have a problem,
During pregnancy, herpes simplex only causes concern:
- If the mother has a first infection during the last few months of pregnancy because there may not be time for the baby to acquire antibodies from the mother before the birth. Taking aciclovir 400 mg three times daily will probably be prescribed by your obstetrician and may prevent the need for a C-section.
- If baby is being born before 32 weeks (very premature). These babies do not have full antibody protection so they could be infected during the birth if the mother has sores.
In these cases, there is a danger that the baby could contract herpes simplex so a Caesarean-section is usually performed. Women who do not have genital herpes should be careful not to catch it in the last two months of pregnancy – as explained above. This means that if their partners are already infected (facially or genitally) they should avoid contact that might transmit the virus to the mother.
A referenced “Pregnancy and Childbirth” leaflet is available to members.
If a baby under 1 month old develops herpes simplex, we call it neonatal herpes. This is very rare, and usually this is because the mother does not have herpes simplex herself, so the baby has no antibodies. Because it is so uncommon, it gets written about: read the article on a baby who caught herpes after childbirth.
The NHS Choices website has more about babies with herpes.
Can I pass genital herpes on to a baby or toddler?