NEW YORK (TrustLaw) - Child marriage, which steals the innocence of millions of girls worldwide and often condemns them to lives of poverty, ignorance and poor health, is one of the biggest obstacles to development, rights groups say.A girl under the age of 18 is married every three seconds -- that's 10 million each year -- often without her consent and sometimes to a much older man, according to the children's charity Plan UK. Most of those marriages take place in Africa, the Middle East or South Asia."This is one of the biggest development issues of our time and we're committed to raising the voices of millions of girls married against their will," Plan UK head Marie Staunton said in her introduction to "Breaking Vows," a recent global report on child marriage.From horrific childbirth injuries to the secret sale of "drought brides," the consequences of child marriage are explored in a multimedia documentary by TrustLaw, a legal news service run by Thomson Reuters Foundation (childmarriage.trust.org)."Young children have babies -- your life is ruined, your education is ruined," said Kanta Devi, who was 16 when she married in Badakakahera village in India's Rajasthan state."You become upset with everything in your life," she told TrustLaw.The U.N. Convention on the Rights of the Child considers marriage before the age of 18 a human rights violation.But according to the International Center for Research on Women (ICRW), there are more than 50 million child brides worldwide, a number that is expected to grow to 100 million over the next decade.