Contraceptive use by women across different sexual orientation groups

Objectives: To examine contraceptive methods used across sexual orientation groups. Study Design: We collected data from 118,462 female participants in two longitudinal cohorts-the Nurses' Health Study (NHS) 2 (founded in 1989, participants born 1947-1964) and NHS3 (founded in 2010, born 1965-1995). We used log-binomial models to estimate contraceptive methods ever used across sexual orientation groups and cohorts, adjusting for age and race. Results: Lesbians were the least likely of all sexual orientation groups to use any contraceptive method. Lesbians in NHS2 were 90% less likely than heterosexuals to use long-acting reversible contraceptives (LARCs; adjusted risk ratio [aRR]; 95% confidence interval [CI]: 0.10 [0.04, 0.26]) and results were similar for other contraceptive methods and in the NHS3 cohort. Compared to the reference group of completely heterosexual participants with no same-sex partners, those who identified as completely heterosexual with same-sex partners, mostly heterosexual, or bisexual were generally more likely to use any method of contraception. Use of LARCs was especially striking across sexual minority groups, and, with the exception of lesbians, they were more likely to use LARCs; as one illustration, NHS3 bisexuals were more than twice as likely to use LARCs (aRR [95% CI]: 2.01 [1.67, 2.42]). Conclusions: While certain sexual minority subgroups (e.g., bisexuals) were more likely than heterosexuals to use contraceptive methods such as LARCs, lesbians were less likely to use any method. (C) 2019 Elsevier Inc. All rights reserved.