 - Leave us kids alone: A look at child marriage in the US and beyondBette Brown | December 15, 2018More than 12m girls around the world, some not even teenagers, are married before the age of 18.There were at least 207,468 such marriages in the States between 2000 and 2015, or an average of almost 40 a day.Child marriage, defined as any formal marriage or informal union where one or both parties are under 18, is banned outright in only two US states.But now a number of states have been galvanised into action to try to halt the practice.