A child marriage is a marriage in which one or both participants are minors, often before the age of puberty. Child marriages are common in many parts of the world, especially in parts of Asia and Africa. The United Nations considers those below the age of 18 years to be incapable of giving valid consent to marriage and therefore regards such marriages as a form of forced marriage; and that marriages under the age of majority have significant potential to constitute a form of child abuse. In many countries, such practices are lawful or — even where laws prohibit child marriage — often unenforced. India has more child brides than any other nation, with 40% of the world total. The countries with the highest rates of child marriage are: Niger (75%), Central African Republic and Chad (68%), and Bangladesh (66%).