Hormonal contraception
Use of hormonal contraceptives and risk of HIV-1 transmission: a prospective cohort study
Renee Heffron, Deborah Donnell, Prof Helen Rees, Connie Celum, Nelly Mugo, Edwin Were, Guy de Bruyn, Edith Nakku-Joloba, Kenneth Ngure, James Kiarie, Robert W Coombs, Jared M Baeten, The Lancet Infectious Diseases, Early Online Publication, 4 October 2011