• Follow us on

Herpes and pregnancy

What is the risk of herpes in pregnancy?

Transmission of herpes simplex virus (HSV) infection from mother to baby can occur when the mother has active genital herpes lesions at the time of a vaginal birth. Herpes infection in the newborn baby is a serious condition and is associated with a risk of neonatal death. Most poor outcomes for babies occur where the mother is unaware she has had a herpes infection.

Symptoms of genital herpes

Primary infection

The first episode of infection can be associated with severe symptoms including painful genital ulcers, pain passing urine or inability to pass urine, fever and headache. However, in some people the infection can be mild or without any recognised symptoms.

Recurrent episodes

People with recurring episodes of genital herpes tend to have milder symptoms and fewer lesions, or no symptoms at all. Before visible lesions are seen patients may experience itching or pain.

Mother to infant transmission

The most common mode of transmission is via direct contact of the baby with infected vaginal fluid during birth. Infection in the baby prior to labour and birth is uncommon. The use of prophylactic antiviral medication has been shown to reduce the amount of virus present at the time of birth but does not completely eliminate the risk of transmission to the baby. The risk of infection in the baby depends on whether the woman has had herpes in the past and if active lesions are present at the time of labour or birth. 

Women with a known history of genital herpes prior to pregnancy

Women who have had genital herpes lesions before becoming pregnant are not likely to transmit herpes to their baby. However, transmission from mother to baby can occur if the mother has a recurrence at the time of birth; although, the risk is much lower than if the infection is occurring for the first time in pregnancy.

For this reason, preventive antiviral therapy with acyclovir is often recommended from 36 weeks for women with one or more recurrences during pregnancy. A caesarean birth is usually offered to women who experience an outbreak of symptoms at the time of labour or rupture of membranes if close to term.  As a vaginal birth in the presence of active recurrent lesions still presents a low risk of infection to the baby, the recommendation for either a vaginal birth or caesarean birth will be determined by many factors including preferences of the woman.

Caesarean birth is not recommended for women with recurrent genital herpes who have no evidence of active lesions at the time of birth or where non-genital lesions are present.

Women who have their first episode of herpes in pregnancy

Women who have their first outbreak of genital herpes in the second half of pregnancy, or close to time of birth if baby is born early, are at risk of transmitting herpes to their newborn. Antiviral therapy is prescribed to the mother during pregnancy to reduce the length of time lesions are present and reduce the risk of complications in the mother. Caesarean birth is often recommended to avoid exposure of the baby to vaginal secretions which may contain high levels of the virus during a first time infection.

For women with no history of herpes, but who have an infected partner

Women with no history of genital herpes whose partner has a history of cold sores (generally HSV type 1) or genital herpes (generally HSV type 2) should avoid oral, vaginal and anal sex during the last 12 weeks of pregnancy. Condoms are recommended during the entire pregnancy.

Care of the baby after birth

If there is concern regarding possible HSV exposure and infection, the baby should be monitored in hospital after birth. Where the risk of transmission of the infection to the baby is high then the baby will need treatment with intravenous (via a plastic drip inserted into baby's vein) antiviral medication and may require blood tests, swabs and a lumbar puncture to take a sample of fluid from baby's back to test for the infection.

Mater acknowledges consumer consultation in the development of this patient information.
Mater Doc Num: PI-CLN-430120
Last modified 25/3/2020.
Consumers were consulted in the development of this patient information.
Last consumer engagement date: 24/3/2020
For further translated health information, you can visit healthtranslations.vic.gov.au/ supported by the Victorian Department of Health and Human Services that offers a range of patient information in multiple languages.
Share this pageAdd to Twitter Add to Facebook Add to LinkedIn Add to Google Bookmarks

Mercy. Dignity. Care. Commitment. Quality


Was this information helpful?


 Security code

Please note: we will endeavour to respond to your enquiry within five (5) business days.