Girls as young as 10 married off—often to older men—in countries including Afghanistan, Yemen, India and Somalia and one girl under 15 is married every seven seconds, according to a report by Save the Children.
"Child marriage starts a cycle of disadvantage that denies girls the most basic rights to learn, develop and be children," said Save the Children International chief executive officer Helle Thorning-Schmidt.
‘Early marriage not only deprives girls of education and opportunities but increases the risk of death or childbirth injuries if they have babies before their bodies are ready.’
"Girls who marry too early often can't attend school, and are more likely to face domestic violence, abuse and rape. They fall pregnant and are exposed to STIs including HIV."
The report ranks countries from the best to the worst in which to be a girl, based on child marriage, schooling, teen pregnancy, maternal deaths and number of female lawmakers.
Niger, Chad, Central African Republic, Mali and Somalia were ranked at the bottom of the index. Researchers say conflict, poverty and humanitarian crises are major factors that leave girls exposed to underage marriage.