Sexually transmitted diseases (STDs), including Human Immunodeficiency Virus (HIV) infection, and unintended pregnancy are critical problems among young adults, especially in minority populations. Although the same sexual behaviors lead to both, many widely used contraceptive methods protect only against pregnancy. Likewise, health care delivery is often oriented toward one but not both risks. Family planning clinics may not screen for SIDs, so asymptomatic or atypical disease can go unrecognized. These clinics may also present contraceptive options in a way that does not take STD prevention into account. Available barrier methods (such as condoms with spermicide) prevent both pregnancy and STDs conditions. However, these methods are not widely used, even in populations in which the risk of STD is relatively high. This is particularly troublesome because new and more effective microbicides that prevent STD/HIV transmission are likely to share some of the characteristics of existing barriers. Factors influencing use of these methods (including associated side effects) are poorly understood, making it difficult to design an effective intervention. In short, we need to know more about how and why individuals -- and couples --choose to accept or reject barrier methods. In addition, research infrastructures and methodological issues need to be established and refined to facilitate testing of new products once they are developed. We propose to study factors that affect the acceptability of over-the- counter (OTC) barrier methods in a sample of women and their male sexual partners. We will select women who are under 25 years old who seek contraceptive services at family planning and teen clinics. We will identify factors associated with acceptance or rejection of barrier methods. In addition, couples will be followed to identify factors associated with patterns of use over time and to estimate the incidence of associated adverse reproductive health outcomes. Our five year study will include a detailed evaluation of demographic, behavioral factors, anatomical changes, and microbiologic effects associated with barrier contraceptive use. We will also consider aspects of the sexual partnership and will focus on psychosocial factors using the sexual negotiation model (SNM), a model for decision-making within partnerships based on social learning theory. Finally, we will consider characteristics of the contraceptive product itself that affect choice of method and consequences of use.