Unintended pregnancy is a public health problem and an unmet medical need worldwide; it is among the most troubling public health problems and a major reproductive health issue. Unintended pregnancies occur for a variety of reasons, in particular, the lack of access to a preferred contraceptive, incorrect use of a method, discontinuation of contraceptive use, and misconceptions about contraceptive methods. This book will: define the meaning of unintended pregnancy, explore the estimated proportion, risk factors and consequences related to unintended pregnancy, examine what drives unintended pregnancy rates and trends, identify groups at high risk of unintended pregnancy.