Context: Advance provision of emergency contraception (EC) may increase timely access and improve effectiveness, but the impact on adolescent sexual and contraceptive behaviors is not known.

Objective: To determine whether adolescents given advance EC have higher sexual and contraceptive risk-taking behaviors compared to those obtaining it on an as-needed basis.

Design and setting: Randomized trial conducted at urban, hospital-based adolescent clinic in Pittsburgh, PA, from June 1997 to June 2002.

Participants: 301 predominantly minority, low-income, sexually active adolescent women, age 15-20 years, not using long-acting contraception.

Interventions: Advance EC vs instruction on how to get emergency contraception.

Outcome measures: Self-reported unprotected intercourse and use of condoms, EC, and hormonal contraception ascertained by monthly 10-minute telephone interviews for 6 months post-enrollment. Reported timing of EC use after unprotected intercourse.

Results: At both 1- and 6-month followup interviews, there were no differences between advance EC and control groups in reported unprotected intercourse within the past month or at last intercourse. At 6 months, more advance EC participants reported condom use in the past month compared to control group participants (77% vs 62%, P=0.02), but not at last intercourse (advance EC 83% vs control 78%, P=0.34). There were no significant differences by group in hormonal contraception use reported by advance EC or control groups in the past month (44% vs 53%, P=0.19) or at last intercourse (48% vs 58%, P=0.20). At the first followup, the advance group reported nearly twice as much EC use as the control group (15% vs 8%, P=0.05) but not at the final followup (8% vs 6%, P=0.54). Advance EC group participants began their EC significantly sooner (11.4 hours vs 21.8 hours, P=0.005).

Conclusions: Providing advance EC to adolescents is not associated with more unprotected intercourse or less condom or hormonal contraception use. In the first month after enrollment, adolescents provided with advance EC were nearly twice as likely to use it and began EC sooner, when it is known to be more effective.