FACTBOX - What is female genital mutilation?

Prisca Korein, a 62-year-old traditional surgeon, holds razor blades before carrying out female genital mutilation on teenage girls from the Sebei tribe in Bukwa district, about 357 kms (214 miles) northeast of Kampala, December 15, 2008.

LONDON (Reuters) - The United Nations passed a resolution on Thursday urging countries to ban female genital mutilation (FGM) - a practice that puts millions of girls a year at risk of serious physical and psychological problems. Below are some facts about FGM.

* An estimated 100 to 140 million girls and women worldwide have been subjected to FGM. In Africa alone, it is thought that three million girls may undergo FGM every year.

* FGM is prevalent in 28 African countries and parts of the Middle East and Asia, notably Yemen, Iraqi Kurdistan and Indonesia. It is also found in industrialised countries among some immigrant populations. Countries where the practice is near universal include Somalia, Sudan, Eritrea, Djibouti, Egypt, Sierra Leone, Mali and Guinea.

* There are several types of FGM. The most serious is called infibulation and involves the partial or total removal of the genitalia and stitching/narrowing of the vaginal opening. Clitoridectomy is the partial/total removal of the clitoris and/or hood. Excision is the partial/total removal of the clitoris and labia. FGM also includes all other harmful practices to the genitalia like pricking, piercing, scraping and cauterising.

* FGM is mostly carried out between infancy and 15. The procedure is arranged by the women in the family.

* It is usually performed by traditional cutters who may use anything from razor blades to scissors, broken glass or tin can lids. However there is an increasing trend in some countries like Indonesia for hospitals to perform FGM.

* FGM is found among Muslim and Christian communities. It is also practised by followers of some indigenous religions. People often believe FGM is required by religion, but it is not mentioned in the Koran or any other religious text.

* Reasons for carrying out FGM vary. Some communities believe it preserves a girl's virginity, prevents promiscuity after marriage and increases male sexual pleasure. Parents say it is an act of love because it purifies the girl, brings her status and prepares her for marriage. It is also mistakenly believed to enhance fertility and make childbirth safer for the baby.

* FGM can cause severe bleeding, pain, shock, recurrent urinary tract infections, cysts and infertility. It increases the risk of labour complications and newborn deaths. The procedure itself can prove fatal.

* A recent study in Iraq found girls who had had FGM were more prone to post-traumatic stress disorders, depression and other psychological disturbances than girls who hadn't. Campaigners liken the psychological effects to those suffered by rape victims. The silence surrounding FGM may also compound the girl's sense of isolation.

* FGM has been banned by 20 of the 28 FGM-practising countries in Africa as well as many industrialised countries. But enforcement of the law is usually weak and prosecutions are rare.

* FGM violates a plethora of international treaties which many FGM-practising countries have agreed to. These include the U.N. Convention on the Elimination of All Forms of Discrimination against Women, the U.N. Convention on the Rights of the Child and the Maputo Protocol on women's rights adopted by the African Union. (Sources: World Health Organisation, No Peace Without Justice, Equality Now) For more on FGM see this package of stories, videos and graphics by the Thomson Reuters Foundatihere (Reporting by Michelle Nichols; Editing by Tim Pearce and David Brunnstrom)