Contraceptive implant discontinuation at one year in adults and adolescents: Implications for adolescent reproductive health services.

OBJECTIVE

Contraceptive implants last for 3-5 years and are a highly effective and safe method of preventing unintended pregnancy. Adolescents face unique barriers that may predispose them to early discontinuation of contraceptive implants, leading to a higher risk of unintended pregnancy. We compared early contraceptive implant discontinuation rates between adolescents (10-19 years) and adults (20-49 years) and evaluated sociodemographic and clinical factors associated with early contraceptive implant discontinuation.

METHODS

This was a retrospective cohort study that followed 2014 participants who initiated etonogestrel and levonorgestrel contraceptive implants between 2016 and 2021 at King Chulalongkorn Memorial Hospital. Discontinuation of contraceptive implants at 12 months was determined by medical record review. Demographic characteristics and clinical factors were extracted from electronic medical records. A Cox proportional hazard model was used to assess factors associated with implant discontinuation.

RESULTS

The overall rate of contraceptive implant discontinuation at 1 year after initiation was 3.83 per 100 person-years. The rates were significant at 2.84 and 4.16 per 100 person-years for adolescents and adults, respectively, with no statistically significant difference between the two groups, although adolescents trended toward a lower risk. The risk of discontinuation was significantly lower among sequential implant users (adjusted hazard ratio [HR] = 0.29, 95% confidence interval [CI]: 0.10-0.79, P = 0.016). No other demographic or clinical factors were found to be associated with discontinuation. Side effects, mainly abnormal uterine bleeding, were the most common cause of discontinuation.

CONCLUSION

Contraceptive implant discontinuation within 1 year after initiation did not differ significantly between adolescents and adults. A trend toward a lower discontinuation rate was observed among adolescents.