We investigate the immediate social context of contraceptive behaviors: specifically, the intimate relationship. We use the Relationship Dynamics and Social Life (RDSL) study (2008-2012), based on a random sample of 1,003 women ages 18-19 residing in a Michigan county. Women were interviewed weekly for 2.5 years, resulting in an age range of 18-22. We test three sets of hypotheses about change over time within a relationship, using relationship-level within-between models, which compare a couple's contraceptive behaviors across different times in the relationship. First, we find that a couple is less likely to use contraception when the relationship is more intimate and/or committed and that a couple becomes less likely to use contraception over time, regardless of intimacy and commitment. Second, we find that a couple using contraception becomes increasingly likely to choose hormonal over coital methods, but this change occurs as a relationship endures and is unrelated to intimacy and/or commitment. Third, we find that a condom-using couple's consistency does not decline when there is conflict; rather, consistency of condom use declines over time regardless of the relationship's characteristics. We also demonstrate that conflict and power imbalance increase reliance on hormonal methods among those using contraception; conflict decreases consistency among withdrawal (but not condom) users; and nonmonogamy increases reliance on condoms and decreases withdrawal consistency. The strong and consistent link between duration and contraceptive behaviors-regardless of intimacy, commitment, conflict, or power imbalance-suggests that the continual vigilance required for long-term contraceptive use is difficult during early emerging adulthood.
Keywords: Contraception; Emerging adulthood; Relationship dynamics; Transition to adulthood.