Herpes infections affect about 10% of the UK population, though only in one third of cases is an actual diagnosis as such made. It usually presents initially with a flu-like illness, followed by an outbreak of vulval sores, which are very painful and swollen glands in the groin.
By a week to 10 days later these have usually healed over. Sometimes the initial attack is mistaken for a thrush infection, just causing an itch or soreness, seemingly responding to cream or pessaries.
Occasionally it is completely without symptoms at all. The first (primary) attack is usually the most painful. The herpes virus stays in the nerve in the spine and can reactivate causing a secondary attack.
This occurs on average at 3-4 months after the first one, and recurrences return on average 2-3 times per year, but this is extremely variable.
The risk of herpes to pregnancy is greatest if the primary attack occurs after 28 weeks. The mother's initial antibody response can take up to 12 weeks to fully develop.
Secondary attacks are much less of a risk. The risk of herpes is passing the infection to the baby at the time of delivery. Primary attacks also can lead to early labour or poor growth.
Because of these risks, a caesarean section is usually advised at term if a primary attack occurs during pregnancy after 28 weeks, or if there is an active secondary attack at the time of labour.
Should a woman experience signs od herpes during pregnancy, it is critical that she consult a doctor to find the appropriate herpes cure.