Elevated Risk of Bacterial Vaginosis Among Users of the Copper Intrauterine Device: A Prospective Longitudinal Cohort Study
Kathryn Peebles, Flavia Matovu Kiweewa, Thesla Palanee‐Phillips, Catherine A. Chappell, Devika Singh, Katherine Bunge, Logashvari Naidoo, Bonus Makanani, Nitesha Jeenarain, Doerieyah Reynolds, Sharon L. Hillier, Elizabeth R. Brown, Jared M. Baeten, Jennifer E. Balkus, MTN-020/ASPIRE study team, Jared M. Baeten, Thesla Palanee-Phillips, Elizabeth R. Brown, Lydia Soto-Torres, Katie Schwartz, Bonus Makanani, Francis Martinson, Linda‐Gail Bekker, Vaneshree Govender, Samantha Siva, Zakir Gaffoor, Logashvari Naidoo, Arendevi Pather, Nitesha Jeenarain, Gonasagrie Nair, Thesla Palanee-Phillips, Flavia Matovu, Nyaradzo Mgodi, Felix Mhlanga
Abstract
BACKGROUND: Limited evidence suggests that the nonhormonal contraceptive copper intrauterine device (Cu-IUD) may increase bacterial vaginosis (BV) risk, possibly due to increased volume and duration of menses, a common side effect of Cu-IUD use. Although increases in bleeding typically resolve within 6-12 months following initiation, evaluations of the association between Cu-IUD and BV have not included more than 6 months of follow-up. METHODS: This secondary analysis of a human immunodeficiency virus type 1 prevention trial included 2585 African women ages 18-45 followed for up to 33 months. Women reported contraceptive use each month. BV was evaluated by Nugent score in 6-monthly intervals and, if clinically indicated, by Amsel criteria. Andersen-Gill proportional hazards models were used to (1) evaluate BV risk among Cu-IUD users relative to women using no/another nonhormonal contraceptive and (2) test changes in BV frequency before, while using, and following Cu-IUD discontinuation. RESULTS: BV frequency was highest among Cu-IUD users at 153.6 episodes per 100 person-years (95% confidence interval [CI]: 145.2, 162.4). In adjusted models, Cu-IUD users experienced 1.28-fold (95% CI: 1.12, 1.46) higher BV risk relative to women using no/another nonhormonal contraception. Compared to the 6 months prior to initiation, BV risk was 1.52-fold (95% CI: 1.16, 2.00) higher in the first 6 months of Cu-IUD use and remained elevated over 18 months of use (P < .05). Among women who discontinued Cu-IUD, BV frequency was similar to pre-initiation rates within 1 year. CONCLUSIONS: Cu-IUD users experienced elevated BV risk that persisted throughout use. Women and their providers may wish to consider BV risk when discussing contraceptive options.