To evaluate the relationship between body mass and levonorgestrel intrauterine device (LNG-IUD) expulsion in adolescents and young adults (AYA).

A retrospective chart review was conducted of nulliparous females aged 10-24 years who had a 52-milligram LNG-IUD placed between November 2017 and May 2021 by pediatric and adolescent gynecology providers at a tertiary children's hospital, including those who underwent metabolic and bariatric surgery (MBS). Primary analysis focused on 10-19 year olds as they had comparable anthropometrics (namely BMI percentile [BMIP] as defined by the Centers for Disease Control). Descriptive statistics included means, standard deviations (SD), and ranges for continuous variables counts and percentages for categorical variables. Chi-square or Fisher's exact tests were used to assess associations. Logistic regressions were fit to test the associations between BMIP, MBS, and the odds of expulsion.

A total of 588 patients were included in the primary analysis (10-19 years). Mean age was 15.8 years (±2.0). Using BMIP, 15.5% (n = 91) of the sample was overweight and 22.3% (n = 131) were obese. Within 12 months, 33 patients (5.6%) experienced expulsion. Every one-unit increase in BMIP was associated with a 3% increase in the odds of expulsion (P = .008), and each increase in BMIP category (eg, overweight vs average/underweight) was significantly associated with increased odds of expulsion (OR = 2.77-4.28). Patients who had LNG-IUD placement during MBS (n = 43) had higher odds of expulsion (OR = 3.23; P = .024) than other patients.

AYA with higher BMIP and/or who undergo MBS are at increased risk of LNG-IUD expulsion within one year of placement.