Use of the etonogestrel implant and levonorgestrel intrauterine device beyond the U.S. Food and Drug Administration-approved duration.
OBJECTIVE
To evaluate the effectiveness of the contraceptive implant and the 52-mg hormonal intrauterine device (IUD) in women using the method beyond the current U.S. Food and Drug Administration (FDA)-approved duration of 3 and 5 years, respectively.


METHODS
Women willing to continue using their implant or 52-mg levonorgestrel IUD beyond the FDA-approved duration were followed prospectively for contraceptive effectiveness. Unintended pregnancy rate per 100 women-years was calculated. Implant users are offered periodic venipuncture for analysis of serum etonogestrel levels. The Kruskal-Wallis test was used to compare the etonogestrel levels across body mass index (BMI) groups.


RESULTS
Implant users (n=237) have contributed 229.4 women-years of follow-up, with 123 using the etonogestrel implant for 4 years and 34 using it for 5 years. Zero pregnancies have been documented, for a failure rate of 0 (one-sided 97.5% confidence interval [CI] 0-1.61) per 100 women-years. Among 263 levonorgestrel IUD users, 197.7 women-years of follow-up have been completed. One pregnancy was confirmed, for a failure rate of 0.51 (95% CI 0.01-2.82) per 100 women-years. Among implant users with serum etonogestrel results, the median and range of etonogestrel level at 3 years of use was 188.8 pg/mL (range 63.8-802.6 pg/mL) and 177.0 pg/mL (67.9-470.5 pg/mL) at 4 years of use. Etonogestrel levels did not differ by BMI at either time point (3 years: P=.79; 4 years: P=.47).


CONCLUSIONS
Preliminary findings indicate the contraceptive implant and 52-mg hormonal IUD continue to be highly effective for an additional year beyond the FDA-approved 3 and 5 years. Serum etonogestrel levels indicate the implant contains adequate hormone for ovulation suppression at the end of both 3 and 4 years of use.


METHODS
II.
Division of Clinical Research, Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, St. Louis, Missouri.
Colleen
C
McNicholas
Ragini
R
Maddipati
Qiuhong
Q
Zhao
Erin
E
Swor
Jeffrey F
JF
Peipert
D000293:Adolescent; D000328:Adult; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D017135:Desogestrel / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007436:Intrauterine Devices, Medicated; D016912:Levonorgestrel / Q000008:administration & dosage*; D011446:Prospective Studies; D013997:Time Factors; D014481:United States; D014486:United States Food and Drug Administration; D055815:Young Adult
D003271:Contraceptive Agents, Female; C044815:etonogestrel; D016912:Levonorgestrel; D017135:Desogestrel