Body Mass Index and Levonorgestrel Device Expulsion in Adolescents and Young Adults

Objective : To evaluate the relationship between body mass and levonorgestrel intrauterine device (LNG-IUD) expulsion in adolescents and young adults (AYA). Methods : A retrospective chart review was conducted of nulliparous females aged 10-24 years who had a 52-milligram LNG-IUD placed between November 2017-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. Results : 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) had obesity. 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 (e.g. 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. Conclusions : AYA with higher BMIP and/or who undergo MBS are at increased risk of LNG-IUD expulsion within one year of placement.