There are two types of the herpes simplex virus (HSV). The first causes cold sores (blisters usually around the mouth) and the second causes genital sores (blisters around the
genitals). Both types can be easily passed on through contact with the sores when they are active, such as through sex and oral sex. Once you've caught the virus it remains in your body and may reactivate at any time.
Most women with genital herpes have a normal pregnancy and a healthy baby, but see your doctor immediately if you do get genital herpes when pregnant. They may refer you to a specialist for tests and treatment because if your baby catches the virus from you there is a risk they will be affected.
First ever attack during early pregnancy
If you have your first ever attack of herpes during early pregnancy, you may be given
antiviral drugs (aciclovir) to clear up the infection before the baby is born. There is no evidence of any risk to the baby from these drugs.
First attack in the later stages of pregnancy (the last six weeks)
If you have any active genital herpes sores in the later stages of pregnancy (the last six weeks) there is a 40-50% risk that you will pass the virus to your baby. This means the baby will carry the virus.
You may need to take
antiviral drugs (aciclovir) for the last four weeks of your pregnancy to try to clear up the sores before the baby is born. There is no evidence of any risk to the baby from these drugs.
It is likely you will have a
Caesarean section so that your baby does not come into contact with the sores.
There is also a very rare chance your baby will develop a condition called neonatal herpes. This only affects 1-2 in 100,000 babies but can cause various complications including damage to the skin, eyes and
Recurrent attack during pregnancy
If you have an attack of herpes during pregnancy but its not your first attack, there is a much smaller risk of your baby being infected (8%) because you and your baby have already had a chance to develop immunity to the virus.
Caesarean section is not normally considered unless you have symptoms of genital herpes.
Speak to your doctor about breastfeeding if you have active herpes.