Pregnancy and infection with herpes simplex

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Herpes virus infection and pregnancy

Herpes is a very common disease

What is herpes?

The term "herpes" refers to diseases caused by Herpes simplex viruses. These are very common infections. There are two types of herpes virus (HSV1 and HSV2) which can cause infections on the lips or the genitals.
Once contracted (primary infection), the herpes virus travels through the sensory neurons in the infected area and lodges itself in a ganglion, where it remains dormant. It becomes latent for a period that can range from several weeks to several years, or even be permanent. Usually, however, the virus reappears from time to time in the area where it was contracted: these are herpes outbreaks, also known as flare-ups or recurrences. These flare-ups are triggered by factors such as stress, fatigue, and weakened immune defences.

What are the symptoms of diseases caused by herpes?

1. Labial herpes, or "cold sores":


Sometime before a cold sore appears, symptoms occur that indicate that a flare-up is coming. A small area around the outline of the mouth may feel hot, with a tight, burning sensation, before redness appears, with tingling and itching.


Labial herpes generally appears on the outer edge of one side of the lip, at the junction where the skin and mucous membrane meet. It manifests itself as a cluster of blisters which become crusted over. Labial herpes is contagious from the time the first signs of a flare-up appear until the blisters are crusted over.​​​​​​

​​​​​​​​​​​​​​2. ​​​​​​​Genital herpes:
Genital herpes can go completely unnoticed. Some people, both men and women, may have been in contact with the virus and never developed herpes symptoms. It is possible for them to transmit the virus to a partner, as the virus will be present on their mucous membranes from time to time without any symptoms.

The initial infection with the virus (or primary infection) often goes unnoticed. It may, however, cause mild or moderate herpes lesions in the affected area. These are small blisters which appear in clusters and can cause itching, a burning sensation, discomfort or pain. Larger and more painful lesions may also appear on the genitals or neighbouring areas (thighs, buttocks), which may be accompanied by sensitivity issues (tingling, etc.). The symptoms of a recurrence are identical to those of the initial infection. The lesions take 7 to 10 days to heal.

What are the risks during pregnancy?

Early treatment is required when a pregnant woman is found to have genital herpes. Certain precautions should be taken when the baby is delivered, to avoid transmission from mother to child.

The symptoms of genital herpes (primary infection or recurrence) are similar in all women, whether or not they are pregnant. The clinical signs are looked for carefully, particularly in the last month of pregnancy. If you have already had genital herpes, inform the doctor or midwife monitoring your pregnancy straight away.
If you develop any painful lesion or irritation of the genitals, or if you have oral sex and your partner has a cold sore, talk to your doctor or midwife immediately.

A newborn baby can be infected with the herpes virus in three ways:

• during pregnancy, if the mother has a primary herpes infection. In this case, the virus present in the mother's blood crosses the placenta and infects the foetus. This risk is very low.
• during delivery of the baby: the herpes virus present in the mother's vaginal secretions infects the baby as it passes through the genital passages. This is the most common method of infection.
• during the first days of life, the virus can be transmitted by the mother or another family member excreting the virus from a genital or labial herpes lesion.

How can I avoid getting herpes during pregnancy?

If you have never had genital herpes, take a few measures to ensure that you aren't infected during your pregnancy:

• If your partner has an outbreak of genital herpes, avoid sexual contact, even protected sex using a condom.
• If your partner has already had genital herpes but isn't having a flare-up, use condoms. Your partner may be carrying the virus without having any symptoms.
• If you or your partner has a labial herpes lesion (or a cold sore), do not have oral sex. The virus present on the lips may be transmitted to the other partner's genitals.