Effectiveness of Prolonged Use of IUD/Implant for Contraception

This prospective cohort study will evaluate 675 LNG-IUD users and 675 Etonogestrel (ENG) Implant users who are within 6 months of expiration or beyond the end of the FDA-approved duration. Participants will be contacted via telephone and either scheduled to enroll in person or be mailed the consent form before participation in the EPIC study. After the signed consent form is obtained, participants will also be asked to complete a brief telephone or in-person questionnaire on sociodemographic, medical and reproductive history, sexual and contraceptive history, history of unintended pregnancy and substance abuse. During the informed consent process, implant users will also be offered to participate in an arm of the study that will randomize them (if they consent) to either keeping their subdermal implant in or have it removed and replaced with a new subdermal implant. The randomized control trial subset allows us to compare effectiveness to that of a new implant.

It also allows us to assess "other contraceptive use" (e.g. condom use) in both groups.

Participants will also be asked if they are interested in providing a blood sample for analysis of etonogestrel assay levels at baseline enrollment and annually. If Follow-up phone interviews will occur every 6 months for 36 months beyond the expiration of their method. The investigators will attempt to validate all pregnancy outcomes with medical chart reviews.