Born into an impoverished family in Hodeidah, Fawziya was forced to drop out of school and married off to a 24-year-old man last year, al-Qureshi said.
Child brides are commonplace in Yemen, especially in the Red Sea Coast where tribal customs hold sway. Hodeidah is the fourth largest city in Yemen and an important port.
More than half of all young Yemeni girls are married off before the age of 18 -- many times to older men, some with more than one wife, a study by Sanaa University found.
"For us in UNICEF, it is the worst form of child abuse," ur-Rehman said, referring to child marriages. "And here, (in) the case of Fawziya, is one child giving birth to another child and in the process she lost her life."
While it was not immediately known why Fawziya's parents married her off, the reasons vary. Sometimes, financially-strapped parents offer up their daughters for hefty dowries.
Marriage means the girls are no longer a financial or moral burden to their parents. And often, parents will extract a promise from the husband to wait until the girl is older to consummate the marriage.
The issue of Yemeni child brides came to the forefront in 2008 with 10-year-old Nujood Ali.
She was pulled out of school and married to a man who beat and raped her within weeks of the ceremony.
To escape, Nujood hailed a taxi -- the first time in her life -- to get across town to the central courthouse where she sat on a bench and demanded to see a judge.
After a well-publicized trial, she was granted a divorce.
The Yemeni parliament tried in February to pass a law, setting the minimum marriage age at 17. But the measure has not reached the president because many parliamentarians argued it violates sharia, or Islamic law, which does not stipulate a minimum age.
UNICEF has been pushing Yemen's parliament to pass legislation banning child marriage which ur-Rehman said is the reason why Yemen has such a high maternal mortality rate.
"There's no accountability for now when a child dies in the process of childbirth and there are so many cases," he said. "The only punishment ... is the one who is suffering silently."