摘要:OBJECTIVES: This study investigated rates of discontinuation of the recently introduced injectable contraceptive depot medroxyprogesterone acetate (DMPA) and postdiscontinuation rates of unprotected intercourse and unintended pregnancy. METHODS: A sample of 402 low-income, urban, minority women were interviewed when they initiated DMPA use and 12 months later. RESULTS: The 12-month life-table discontinuation rate was 58%, with half of the discontinuers stopping after only one injection. Menstrual changes and other side effects were the most frequently cited reasons for discontinuation. Approximately half of the discontinuers at risk for unintended pregnancy either did not make the transition to another contraceptive or used contraception only sporadically. The cumulative unintended pregnancy rate by 9 months postdiscontinuation was 20%. CONCLUSIONS: DMPA initiators were at substantial risk for unintended pregnancy because most quickly discontinued use and did not make the transition to consistent use of another contraceptive.