Intrauterine devices (IUDs), both copper and hormonal, are highly effective and convenient forms of long-term contraception, with failure rates below 1%. However, complications such as malposition, expulsion (reported in 10-30% of postpartum insertions), and migration remain clinically significant. Despite these risks, current guidelines for IUD candidacy do not incorporate individualized risk factors. This is problematic, as migration can cause complications, including uterine, bladder, and gastrointestinal perforation, abnormal bleeding, pain, and unintended pregnancy. This study aims to perform a structured narrative synthesis of patient-specific and procedural factors associated with IUD malposition, migration, and expulsion to inform a risk-stratified framework for IUD candidacy. A comprehensive literature search was conducted using PubMed, Embase, and CINAHL Ultimate, following PRISMA recommendations. Inclusion criteria included studies of reproductive-age individuals with IUDs, focusing on postpartum, post-abortion insertion, or parity. Studies published before 2015, non-English articles, and animal studies were excluded. Screening and qualitative synthesis were conducted by independent reviewers with group consensus. IUD displacement was associated with higher BMI, younger age, multiparity, and certain racial and ethnic groups. Immediate postpartum insertion and vaginal delivery were associated with higher expulsion risk, whereas breastfeeding, delayed insertion, and cesarean delivery were protective. Additional factors included heavy menstrual bleeding, menstrual cup use, device characteristics, uterine anatomy, and provider experience. Smaller IUDs and ultrasound-guided insertion were associated with improved positioning and lower complication rates. These findings support a risk-stratified approach to improve patient selection and outcomes. Interpretation is limited by heterogeneity in study design, variable outcome definitions, and study populations.
