This post is the introduction to a monthly series of posts, Stories Behind the Statistics, produced by the IYWG for the Gates Foundation. The original post is available on the Gates Foundation blog, Impatient Optimists.

For many women, receiving a positive pregnancy test can be one of the happiest moments of their lives; for an adolescent it can be terrifying. Approximately 16 million girls between the ages of 15 and 19 give birth each year and, in developing countries, approximately one-third of adolescent girls give birth before their 20th birthday. The social impacts of pregnancy on adolescent girls can be devastating: girls who become pregnant often face discrimination within their communities, drop out of school, and are sometimes forced into early marriage. Girls who become pregnant are more likely to have a lower income and have more children at shorter intervals throughout their lifetime. In contrast, young women who avoid unintended pregnancy are more likely to stay in school; participate in the work force; and have healthier, better-educated children.

Not only does pregnancy during adolescence have negative social impacts, it poses significant risks to the health and lives of young women. Pregnancy in adolescence is life-threatening for many.  Childbirth-related complications are the number one cause of death among girls ages 15-19.  Pregnancy during adolescence also increases the risk of anemia, postpartum hemorrhage, prolonged obstructed labor, obstetric fistula, malnutrition, and mental health disorders, including depression.

Many factors—such as poverty, gender inequality, lack of education, and early marriage—place adolescent girls at high risk of early or unintended pregnancy. But, unintended and early pregnancy is preventable. Interventions to help girls stay in school and delay marriage can have numerous positive effects on the lives of young women, including decreasing their risk of unintended pregnancy. Proven interventions such as comprehensive sex education for both in-school and out-of-school youth, as well as improved access to contraception (including condoms), can vastly reduce high rates of pregnancy among this age group.

The next two blog entries in this series, published on Impatient Optimists next week, written by young people living in Zimbabwe and Nepal, will provide first-hand accounts of the challenges many adolescents who become pregnant face. These two authors will share the stories behind these striking statistics.

To learn more about adolescent pregnancy visit the Interagency Youth Working Group’s “Adolescent Pregnancy” topic page.

 Are you inspired to act on behalf of women and girls who deserve the opportunity to determine their own futures and who desperately need access to family planning education and contraceptives? Look for ongoing information about, and ways to pledge support for, the upcoming Family Planning Summit on July 11, 2012. The Summit is being hosted by the Gates Foundation and the UK’s Department for International Development (DFID). It will address the unmet need for the 120 million women who, over the next eight years, will want contraceptives but won’t have access to them unless we invest in women and girls and put family planning front and center on the global agenda. Join the conversation with @gatesfoundation and check Impatient Optimists regularly for details.