Efficacy Trial of CDB 2914 for Emergency Contraception

Inclusion Criteria: Menstruating women at least 18 years old; Give voluntary, written informed consent, and agree to observe all study requirements; Request emergency contraception within 72 hours (3 days) after unprotected coitus, as defined by lack of contraceptive use, or condom breakage (including condoms lubricated with spermicide) or other barrier contraceptive method failure; Reports that all acts of unprotected coitus during the current cycle are within 72 hours prior to enrollment; Willing to abstain from further acts of unprotected intercourse during that cycle; History of regular menstrual cycles (mean length of 24-42 days with intra-individual variation of ±5 days); At least one normal menstrual cycle (2 menses) post delivery or abortion; If subject recently discontinued hormonal contraception, one normal menstrual cycle (2 menses) must have been completed before entry in the study For women with a recent history of Depo Provera use, the most recent injection must be at least 3 months before study entry and the subject must have had at least one normal menstrual cycle (2 menses); Available for follow-up for at least the next four weeks. Exclusion Criteria: Currently pregnant (positive high-sensitivity urine pregnancy test); pregnant or breast-feeding within the past two months; use of hormonal methods of contraception during the current or previous two cycles; current user of IUD; tubal ligation; partners with history of vasectomy; unsure about the date of the last menstrual period (+3 days); irregular menstrual cycles as defined in the inclusion criteria; nausea and vomiting within the previous two weeks; impaired hypothalamic-pituitary-adrenal reserve or oral glucocorticoid replacement therapy in the last year. Subjects cannot be currently enrolled in any other investigational trial or re-enrolled in this study.