The search yielded 1488 titles (Figure 1).15 Following exclusions, 22 publications (2 guidelines and 20 scientific articles) were retained. An additional 5 scientific articles were added from 1 author’s (E.G.) bibliographic database. All 27 publications were extracted and assessed for quality. Two articles were rejected because of low quality score: Rocca et al21 (score 17% with CASP Systematic Review Checklist) and Honorato et al22 (score 25% with the JBI checklist for analytical cross-sectional studies). Quality scores were greater than 85% for most of the selected articles and reviews.

Flowchart for literature search and study selection based on PRISMA guidelines for systematic reviews

Efficacy and safety of the ENG contraceptive implant beyond the approved duration of use (Table 1).14,23-32 No pregnancy occurred in 783 participants who extended implant use for 1 additional year14,25,28 or in 306 participants who extended use for 2 additional years.14,25 Two prospective studies24,25 and 1 cross-sectional study23 demonstrated median serum ENG levels above the theoretical minimum threshold for ovulation inhibition (90 pg/mL)27 after 3, 4,23-25 and 5 years25 of implant use. A weak relationship between serum ENG and time since insertion was demonstrated in 1 study,23 while no association with BMI was found in 3 studies.23-25 The most frequent adverse events in years 4 and 5 were irregular bleeding, reported by 46.2% of users; headache, reported by 31.8% of users; and lower abdominal pain, reported by 17.9% of users.14

Summary of publications on prolonged duration of etonogestrel contraceptive implants: A) Scientific articles and B) guidelines.

In 2022, the Society of Family Planning (SFP)32 recommended informing patients that the contraceptive efficacy of the 68-mg ENG implant was maintained beyond the 3 to 5 years’ duration currently approved by the US Food and Drug Administration (grade 1A evidence).

Efficacy and safety of the Cu-IUD beyond the approved duration of use (Table 2).32-39 The studies by Rowe et al from 1997 and 2016 reported no pregnancies in patients using the TCu380A IUD during, respectively, 1440 women-years of observation from 8 to 12 years after insertion (n=356) and 1342 women-years of observation from 7.2 to 11 years after insertion (n=682).33,37 Combining data from the 1997 study by Rowe et al33 and a 2005 study from Bahamondes et al (n=228),34 Ti et al38 calculated an overall pregnancy rate of 0.0 per 100 women-years (95% CI 0.0 to 0.8) for years 11 and 12. Sivin35 combined data from the Population Council, the World Health Organization, and Bahamondes et al (2005)34 and reported no pregnancies in 1886 women-years of observations from years 10 through 15.

Summary of publications on prolonged duration of Cu-IUDs: A) Scientific articles and B) guidelines.

The expulsion rate was 1.3 per 100 women-years for years 11 and 12, and 0.7 per 100 women-years from 7.2 to 11 years, in Rowe et al (1997)33 and Rowe et al (2016),37 respectively. In Bahamondes et al (2005),34 the expulsion rates were 2.1 and 1.1 per 100 women-years in years 11 and 12, and 3 expulsions occurred from years 13 to 16. In comparison, in Rowe et al (2016),37 the cumulative expulsion rate was 3.49 per 100 women-years in the first year after insertion, and 7.30 per 100 women-years after 5 years. Bleeding or pain or both led to IUD discontinuation in 4.6 per 100 women-years between years 10 and 12, and 1.2 per 100 women-years from 7.2 to 11 years, in Rowe et al (1997)33 and Rowe et al (2016),37 respectively. In Bahamondes et al (2005),34 these figures were 1.6, 1.1, 2.5, 3.4, and 0 per 100 women-years at years 11, 12, 13, 14, and 15 to 16, respectively. In Rowe et al (2016),37 the cumulative rates for discontinuation due to heavy bleeding and pain were 2.42 and 1.72 per 100, respectively, 1 year after insertion, and 7.42 and 5.01 per 100, respectively, after 5 years. Other problems were found to be rare or nonexistent.33-35,37

The 2014 and 2022 SFP guidelines32,39 recommended prolonged use of the 380-mm2 Cu-IUD (equivalent to TCu380A) for 12 years, regardless of the patient’s age at insertion. The 2022 SFP guideline32 recommended that the use of all 380-mm2 Cu-IUDs be extended beyond 12 years, and up to 20 years or until menopause, for patients older than 30 years of age at the time of insertion.

Efficacy and safety of the LNG-IUS beyond the approved durations of use (Table 3).24-26,32,37-53 Prolonged use was reported only for 52-mg LNG-IUS. No pregnancies were reported in 9 studies at different durations of use, ranging from year 649,50 to years 6 and 7,40,41 years 6 to 8,44 year 8,51,52 years 9 and 10,53 years 6 to 11,37 and years 6 to 15.49 A total of 2 pregnancies were reported in year 6 in 2 studies24,52 (n=625), and 4 pregnancies were reported in year 7 in 3 studies (n=1228).25,51,52 In a 2020 meta-analysis of 4 studies25,38,41,49 by Ti et al,38 the cumulative pregnancy rate during years 6 and 7 was 0.02 per 100 women-years.

Summary of publications on prolonged duration of LNG-IUS: A) Scientific articles and B) guidelines.

Expulsions occurred rarely per additional year in several descriptive studies.40,50-53 Rowe et al (2016)37 observed an expulsion rate of 0.7, 1.2, and 0.8 per 100 women-years, in years 6, 7, and from years 8 to 11, respectively. In Bahamondes et al 2018,49 the cumulative rates of discontinuation (per 100 women-years) due to expulsions were 0.3, 0.6, 0, 1.1, and 2.1 for years 5 to 6, 7 to 8, 9 to 10, 11 to 12, and 13 to 14, respectively.

Regarding menstrual-related adverse events, most studies reported discontinuation rates of less than 5% during each additional year of use.37,40,50-53 In Bahamondes et al (2018),49 cumulative rates (per 100 women-years) of discontinuation due to bleeding or pain were 0.2, 2.3, and 0 for years 5 to 6, 7 to 8, and thereafter, respectively. Other adverse events occurred in very low frequencies in all studies.

Prolonged use of the 52-mg LNG-IUS for 7 years39 or 8 years32 is recommended by the SFP, which also states that contraceptive effectiveness with extended use of 52-mg LNG-IUS is independent of BMI,32,39 and that patients taking cytochrome P450 3A4 inducers might be offered extended use of this IUS.32