Efficacy and Safety of Etonogestrel + 17β-Estradiol Vaginal Ring and Levonorgestrel-Ethinyl Estradiol Combined Oral Contraceptive in Adult Women at Risk for Pregnancy (MK-8342B-062)

The purpose of this study is to assess the contraceptive efficacy of the etonogestrel + 17β-estradiol (ENG-E2) vaginal ring in women between 18 and 35 years of age based on the number of in-treatment pregnancies as expressed by the Pearl Index (PI). The study will also assess the safety and tolerability of ENG-E2 vaginal ring. The levonorgestrel-ethinyl estradiol (LNG-EE) 150/30 μg combined oral contraceptive (COC) will be used as the active comparator.