Unintended pregnancy can carry serious consequences for women and their families. The study estimates the incidence of pregnancy by intention status and outcome at worldwide, regional, and sub regional levels for 2008, and we assess recent trends since 1995. Numbers of births are based on United Nations estimates. Induced abortions are estimated by projecting from recent trends. A model-based approach is used to estimate miscarriages. The planning status of births is estimated using nationally representative and small-scale surveys of 80 countries. Of the 208 million pregnancies that occurred in 2008, the study estimates that 41 percent were unintended. The unintended pregnancy rate fell by 29 percent in developed regions and by 20 percent in developing regions. The highest unintended pregnancy rates were found for Eastern and Middle Africa and the lowest for Southern and Western Europe and Eastern Asia. North America is the only region in which overall and unintended pregnancy rates have not declined.