The measure of unmet need for contraception represents a core concept in the field of family planning and is one of the most important indicators for family planning policy, programs and research. A general concept of unmet need has existed almost as long as the international family planning movement has been in existence, beginning with researchers in the 1960s describing the discrepancy between women's stated desire to limit childbearing and their actual use of contraceptives.1,2 Measurement of this gap between knowledge, attitude and practice-the "KAP-gap"-was included in national family planning studies in developing countries from the 1960s through the 1980s. Charles Westoff and colleagues further refined the concept to take into consideration pregnancy, postpartum amenorrhea, fecundity and women's desire to space births. [3][4][5][6] Recently, Bradley et al. revised the unmet need measure to reduce its complexity and allow for more consistent application across time and countries. 7 The core of the concept, however, remains based on an algorithm that assigns unmet need to women who are married or in union and are fecund, but do not want a child in the next two years and are not using any method of contraception. Pregnant and amenorrheic women are considered to have an unmet need if they say that their current or last pregnancy was unintended.* 6Over the last three decades, recommendations have been made to improve the concept of unmet need, including accounting for the need for more effective family planning among women using traditional methods, 8,9 pregnant and postpartum women's future fertility intentions, 10 husbands' preferences and the unmet need of the couple, 11,12 and the unique contraceptive needs of unmarried women. 8,13 Researchers have also argued that to more effectively gauge actual contraceptive demand, the measure of unmet need should account for women's intention to use contraceptives, 10,14 and that a sizeable proportion of women classified as having an unmet need would not use contraceptives even if they were available. Therefore, using unmet need as the measure of contraceptive demand may be misleading. 15,16 Due to a lack of appropriate longitudinal data, few studies have assessed the value of the unmet need measure for predicting future contraceptive use or compared outcomes among women classified as having an unmet need according to whether or not the women intend to use a method.