Migration of etonogestrel subcutaneous contraceptive implants: systematic review and recommendations for practice.

Introduction: Migration is a rare but serious complication of the etonogestrel contraceptive implant, and little is known about its extent.

Purpose: To document and characterise cases of etonogestrel contraceptive implant migration in the scientific literature.

Methods: A systematic review of Medline, Embase and Global Health databases was carried out between January 2000 and January 2023 to identify articles presenting implant migrations. Narrative reviews, conference abstracts and articles not written in English or French were excluded.

Results: Forty-five articles, mostly published since 2016, were identified (eight case series and 37 case reports), for a total of 148 independent cases of migration: in pulmonary blood vessels (n = 74), in non-pulmonary blood vessels (n = 16) and extravascular (n = 58). Many patients are asymptomatic and migration is often an incidental finding. A non-palpable implant and symptoms related to implant location (intra- or extra-vascular) may be indicative of migration. Inadequate insertion and normal or underweight appear to increase the risk of migration. Scientific societies and authors offer practical strategies to deal with implant migration.

Conclusion: Professionals who insert and remove contraceptive implants must be adequately trained. They need to be on the lookout for implant migration, and promptly refer patients to appropriate care if migration is suspected.