LEVONORGESTREL CAPSULE IMPLANTS IN THE UNITED-STATES - A 5-YEAR STUDY

Objective: To measure effectiveness, adverse event experience, and acc eptability of the Food and Drug Administration-approved variant of lev onorgestrel capsule implants in the United States through 5 years and to examine determinants of these outcomes. Methods: In a prospective, multicenter study, 511 sexually active women selecting contraceptive i mplants were monitored four times in the Ist year, then semiannually t hrough 5 years. Adverse events were elicited by query and physical exa mination, and their incidence was measured. Lifetable analyses compute d pregnancy and other discontinuation rates. Cox regression models exa mined effects of age, parity, and preadmission desire for more childre n on continuation. Removal times were analyzed by analysis of variance . Results: Three pregnancies occurred, yielding a 5-year cumulative ra te of 1.3 +/- 0.8 per 100 users, an average annual rate of three per 1 000 women, and an ectopic pregnancy rate of 0.6 per 1000 woman years. No pregnancies occurred to women weighing less than 79 kg. Prolonged o r irregular menstrual bleeding, followed distantly by headache, weight gain, and mood changes, was the most frequent medical conditions lead ing to removal. Weight gain averaged 1 kg per year. Each annual contin uation rate was above 80 per 100, for a cumulative 5-year rate of 39 p er 100. Continuation was age-dependent, with younger women (younger th an 25 years at entry) having lower 5-year continuation rates than olde r subjects (P < .01). Tissue trauma from deeply placed or poorly align ed implants or severe reactions to local anesthetic affected subjects in 3.1% of removals (nine cases). Conclusion: As measured by annual co ntinuation rates of 80 per 100 or higher and annual pregnancy rates be low one per 100, implant contraception in the United States was found to be highly acceptable and effective, year after year, regardless of the woman's age or family formation status. The cumulative 5-year preg nancy rate, 1.3 per 100, is comparable to that of tubal Ligation. (Obs tet Gynecol 1998;92:337-44. (C) 1998 by The American College of Obstet ricians and Gynecologists.).