Multiple challenges such as high rates of discrimination, poverty and traumatic events, expose American Indian (AI) women to high-risk sexual partnerships placing them at an increased risk for HIV/STI. Characterizing sexual partner networks, or who is partnering with whom, and how partnerships change over time, is essential for translating the concept of sexual health beyond the individual to the partnership and the population of connected emerging adults.

We interviewed 129 AI women age 15–35 years residing on a rural reservation with 189 unique partnerships to understand patterns of relationship formation and dissolution and how these partnerships differ in terms of socio-demographic characteristics, sexual risk behaviour within partnerships, and characteristics of place (e.g., where partners met, where they most often have sex, where the partner lives) to inform prevention interventions.

Of the 129 sexually active AI women, 37% reported > 1 partner in the past 6 months. Women reporting one partner (compared to > 1 partner) report lower 12-months binge drinking: 25.9% vs. 58.3%, p < 0.001) and less alcohol use prior to sex (48.2% vs. 72.9%, p < 0.01). Pertaining to partnership characteristics, the previous partner (P2), placed the participant at higher risk for HIV/STI than the current partner (P1); P2 (as compared to P1) reported higher alcohol use prior to sex (65.0% vs. 51.972.9%, p < 0.05) and partner concurrency (55.0% vs. 17.8%, p < 0.05). Characteristics of place differences: P2 was less likely to live in the same town as the respondent, compared to elsewhere on the reservation or outside the reservation (27.5 vs.42.6, p = 0.06). Lastly, sexual intercourse with P2 (compared to P1) usually took place in “riskier” settings such as a car, bar, or outside (35.0% vs. 10.1%, p < 0.01).

Emerging AI adult women in risky partnerships transitioned to a safer partner overtime. Preventing engagement with risky partners would reduce HIV/AIDS risk.