Genital herpes and pregnancy

Quick facts:

• Herpes is one of the most common skin to skin infections and is also transmitted sexually. It causes mild or no symptoms in most adults.
• In infants, the herpes simplex virus (HSV) causes neonatal herpes which can cause eye or throat infections, damage to the central nervous system, and even death in rare cases.
• The risk of transmission of genital herpes to a baby during pregnancy is very low.
• Babies are most at risk from neonatal herpes if the mother contracts genital HSV in late pregnancy and has no antibodies against HSV at that time.

The herpes simplex virus (HSV) causes genital herpes. There are many types of herpes viruses. Both herpes simplex type 1 (HSV1) and herpes simplex type 2 (HSV2) can infect the genital area. A person can be infected with both HSV1 and HSV2.

Commonly the cause of cold sores, HSV1 tends to occur in the upper half of the body, mainly around the lips and mouth. HSV2 is more commonly the cause of genital herpes. Both viruses are passed from one person to another by close body contact and are very common in Australia.

If you are pregnant and you get genital herpes, it is important to tell your midwife or obstetrician.

If you are someone who has herpes, the risk of transmission to your baby is small (less than 1%). However, there is some risk of transmission if there is a herpes lesion around your genital area while you are in labour.

HSV can also cause problems if you have a first ever infection (primary infection) that causes symptoms in the first part of the pregnancy (may lead to miscarriage). If you are pregnant and have a sexual partner who has a history of HSV, you may decide to use condoms for the duration of the pregnancy, or your partner may take suppressive treatment through the pregnancy to reduce the risk of transmission.

The most common risk is for the mother to pass herpes virus onto the baby at the time of delivery. By talking to your doctor about your history of herpes, precautions can be taken to prevent this.

If you have had HSV for a while, you will have developed antibodies to the virus. These protective antibodies are given to the baby via the placenta and decrease the likelihood of the baby having a severe herpes infection. However, if your first herpes infection is recent, you may not have developed antibodies to the herpes virus. This means that there will not have been a transfer of protective antibodies from mother to baby and the baby is therefore much more vulnerable to having a severe herpes infection.

It is also important to know that some people may have genital herpes and not recognise these lesions when they occur because they are very insignificant in appearance, or there may be no symptoms. You may feel an itch at the vaginal opening and may think you have thrush (genital itch). It is recommended to have a medical check-up if you experience recurrent thrush. It is best to go and see your health provider when you have symptoms they can see and sample to confirm whether or not they are genital herpes.

Other resources

The New Zealand Herpes Foundation provides reassurance and comprehensive information about protecting your baby from genital herpes during pregnancy and birth.

Related Content

• Genital Herpes fact sheet
• Safe Sex fact sheet