( CNN ) -- Throughout my career as a doctor I have traveled from the mountains of Yemen to its deserts . I have seen first hand what happens when children give birth to children . I have seen the tombstones of girls who died too young because they married too young . Yemen is one of only two countries in the world with no legislation on a minimum age of marriage . With a national dialogue underway to establish a new constitution , there is now a chance to establish a safe age of marriage , protecting young girls who are currently married off as young as 9 years old . As I advocate to end child marriage in Yemen , I always remember my best friend at school . We would talk about our future and what we wanted to be when we grew up . We had big aspirations , as young girls should . My friend was the smartest girl in our class . Everything felt possible . But when she was 13 , she was told to leave school to prepare for her wedding . Her dreams ended . We were all so upset . I still remember her wedding day as we tried to support her . It was such a sad day for us all , a stark comparison for so many whose wedding day is remembered as the happiest of their lives . I was lucky . My parents did not want me to marry as a child . They were my firewall , protecting me from the pressure of all the people in my community who said I should marry . They were determined to give me a brighter future . As I carried on my studies , and became a doctor , the image of my friend 's wedding always stayed with me . So many girls in my country do n't have the right to say `` No , I do n't want that man or this kind of life . '' My friend moved away and we did n't stay in touch . My friend 's story is not unusual . The UN estimates that one in three girls in Yemen are married before 18 . Around the world , approximately 14 million girls are married as children every year . The right to choose . To think of all the girls in my country who are forced into marriage , lose their personalities , their happiness and just have to obey what they are told to do , is what drives me forward in my work . Child brides do n't talk about it , but they suffer . A recent study in Yemen has shown that girls who have their rights taken from them in this way do not forgive their parents , and there is a breakdown of family relationships . As a doctor I see the complications young girls are suffering from as they give birth before their bodies are ready . Girls not Brides , a civil society network campaigning against child marriage , suggests that girls under 15 are five times more likely to die giving birth . Read more : Yemeni girl goes on YouTube to plea for education , not marriage . Yemen has one of the highest maternal death rates in the world . According to the White Ribbon Alliance , one in 90 women die in childbirth in my country . I can not bear to continue to watch young women giving up their lives and having to give birth too young . We must support our girls and women by providing better maternal health care , access to family planning and safe abortion . We must work together to end early marriage so that all girls have the right to choose when and whom to marry and are able to finish their education , strengthening the bonds that are so important to us , with our friends and our family . We know how to fix these problems . We can tackle many issues if we tackle early marriage . Together in partnership with the White Ribbon Alliance in Yemen and many other activists we have been campaigning for a safe age of marriage for many years . Since the uprising in 2011 , a new constitution is being drafted in my country . This is an opportunity to establish a minimum age of marriage . But it is a narrow window of opportunity . Too often girls have no voice , no choice , no access . I am determined to help them have a better future . My friend did not fulfill her dream , but by ending child marriage together we can make sure that girls in Yemen and around the world can fulfill theirs . The opinions expressed in this commentary are solely those of Nawal Ba Abbad .
Campaigners in Yemen want law against child marriage in the country . Around one third of girls married before they are 18 , according to the UN . Nawal Ba Abbad says younger marriage leads to more complications during childbirth . Some girls are sent into arranged marriages as young as 9 years old .