In a clinical trial of pre-exposure prophylaxis ( PrEP ) for HIV-1 prevention in HIV-1-serodiscordant couples , we estimated the effectiveness of hormonal contraceptives ( oral contraceptive pills , injectable depot medroxyprogesterone acetate , and hormonal implants ) for pregnancy prevention relative to no contraception among 1785 HIV-1-uninfected women followed up to 36 months .