Introduction
Unintended pregnancy can have grave consequences for women, children, and families, making access to safe and effective contraception a global health priorityThe Evidence for Contraceptive Options and HIV Outcomes (ECHO) Trial found no significant difference in HIV incidence rates among 7,829 African women randomized to either (a) injectable intramuscular depot medroxyprogesterone acetate (DMPA-IM), (b) the levonorgestrel (LNG) implant, or(c) the non-hormonal T-380 copper intrauterine device (Cu-IUD)To date, the association between initiation of three commonly used contraceptives, DMPA-IM, LNG implant, and the Cu-IUD, and concomitant changes in the vaginal environment has not been explored in a randomized trial, which overcomes biases introduced by differences in behavior among women choosing their preferred contraception in observational studies. The recently completed UChoose Trial found differential effects of three contraceptives on the FGT microbiota and cytokine profile