ECPs are a back-up contraceptive method indicated for prevention of pregnancy after sexual intercourse if a primary contraceptive method fails or is not used. This trial will determine how increased access to ECPs affects the probability of pregnancy and three STIs. The STIs tested in the study are chlamydia, gonorrhea, and trichomonas. The trial will also evaluate how ready access to ECPs influences contraceptive or STI-prevention behaviors, particularly use of ECPs themselves, use of condoms, and use of other contraceptive methods.

The trial will be conducted among about 1,490 young women in the United States at high risk for pregnancy and STIs. Sexually active women aged 14 to 24 years who use barrier methods of contraception, oral contraceptive pills, or no contraception will be enrolled. Each woman will be randomly assigned to either an Advance Provision group or a Standard Care group. In the Advance Provision group, women will be given a supply of ECPs free of charge to keep at home in case of need. In the Standard Care group, women will be counseled about ECPs and invited to come to the clinic to obtain them at usual clinic charges when necessary.

Participants will be seen for follow-up at Months 6 and 12. At each visit, participants will be asked about pregnancies, STIs, sexual activity, self-assessed STI and pregnancy risk, and use of ECPs and other contraceptive methods. A specimen will be obtained for chlamydia, gonorrhea, and trichomonas testing.