Effects of Copper Versus Levonorgestrel Intrauterine Devices on Mucosal Microbiota and Barrier Function Among Young African Women

The goal of this clinical trial is to definitively determine whether copper intrauterine device (IUD) or hormonal intrauterine system (IUS) results in greater vaginal microbial diversity after 1 year in women (n= approximately 120) aged 18-40 years, who desire to use a copper IUD or hormonal IUS as contraception, are HIV-negative and could benefit from STI prevention. The main questions it aims to answer are: 1. Whether women assigned to copper IUD vs hormonal IUS have differences in vaginal microbial diversity after 1 year of use 2. Whether women randomized to Copper IUD have reduced genital mucosal barrier integrity as indicated by proteomic signatures 3. Whether women randomized to Copper IUD have greater incidence of high-risk HPV or curable STIs (Ct, Ng, Tv) Participants will be assigned to have either the copper IUD or the hormonal IUS inserted as contraception. After that, they will have blood and vaginal fluids collected every 3 months for one year to look at the bacteria in their vagina, test for sexually transmitted infections, and examine markers of vaginal health. After enrolment, each participant will be followed for 12 months, and at the end of the trial, the participant can continue to use the IUD/IUS or the study clinician can remove it.