Genital warts Dr Rob Hicks Genital warts are the most common sexually transmitted infection diagnosed in genitourinary medicine (GUM) clinics.

In this article

What causes them? Who's affected?

What are the symptoms? How are they prevented?

What's the treatment? Risks during pregnancy

Genital warts are caused by infection with the human papilloma virus. The strains of this virus that cause genital warts are different to the strains that cause warts on the fingers and hands.

It's a sexually transmitted infection spread through intimate contact. This doesn't need to be penetrative sex - close genital contact is enough.

The number of people with genital warts is increasing. Up to 50 per cent of sexually active men and women are infected with the genital wart virus, but usually only a small number of these people develop warts.

Both men and women can get genital warts.

Genital warts may feel like gritty, hard bumps on the skin of the genitals or around the anus before they are seen.

Usually more than one genital wart is present.

When visible, they may appear as flat, smooth, small bumps, or quite large, pink, cauliflower-like lumps. They may itch, but are usually painless.

Practising safer sex by using condoms provides some protection.

A vaccine is available to protects against two types of human papilloma virus (6 and 11) that cause genital warts. This is effective when given before someone is in contact with the virus, meaning - for most people - before they become sexually active.

Genital warts can be treated by painting them with a special liquid. This is done in a genitourinary medicine (GUM) clinic, which will also stock some topical treatments for use at home.

Other treatments include cryotherapy (freezing), cauterisation (burning), laser therapy and surgical removal under general anaesthetic.

During pregnancy, warts can grow in size and obstruct the birth canal, making delivery difficult, or they may bleed as the baby passes through the birth canal. For these reasons, some experts recommend their removal during pregnancy.

Very rarely, a baby will contract the virus and develop warts in the throat, but it's unclear whether treating warts or caesarean delivery prevents this.

The current recommendation is that caesarean delivery should not be performed solely to prevent transmission of the wart virus to the baby, but a caesarean may be recommended if the genital warts might obstruct the baby's delivery or result in excessive bleeding.

Most babies born to mothers with genital wart virus infection are not affected by it.

This article was last medically reviewed by Dr Rob Hicks in April 2008