The Association Between BMI and Adherence After the Insertion of Etonogestrel-Releasing Implant [ID: 1376766

Abstract

INTRODUCTION: The aim of this study is to learn the association between body mass index (BMI) to the incidence of side effects and adherence to treatment of etonogestrel-releasing implant. METHODS: This is a retrospective cohort study, conducted at a single university-affiliated medical clinic, including all women that underwent etonogestrel-releasing implant (Nexplanon, Merck and Co.) insertion between January 2019 to December 2021. Information on patients’ demographic, medical history, obstetrical and gynecological history, and follow-up were collected from women’s electronic medical files. Primary outcome was defined as the rate of implant removal in the obesity classes. The study was IRB approved. RESULTS: Study population included 1,318 women; of them, 466 (35%) requested early removal of the implant. Women’s demographic and clinical characteristics were comparable between women who requested early removal to those with full-length treatment. The median time for removal was 12 (6–20) months from insertion. Irregular bleeding was the most frequent reason for early removal in both groups and more prevalent in the early removal group (239 [51.29%] versus 193 [22%], P=.001). The rate of women with obesity (BMI ≥30 kg/m2) was found lower in the early removal group (163 [35%] versus 350 [41.1%], P=.03) with comparable rates between the groups in class 3 obesity (BMI ≥40 kg/m2) (P=.68). Side effects rate as a compound parameter (including irregular bleeding, heavy bleeding, weight gain, and mood changes) was higher in the group who didn’t have obesity (39.1% versus 32.7%, P=.02). Multi-regression logistic analysis including age, BMI, parity, and side effects found the presence of side effects as the only independent predictor significantly associated with early implant removal (B=1.74, P=.04). CONCLUSION: Adherence to etonogestrel-releasing implant contraception treatment is associated to the presence of side effects that is reported more often in women who do not have obesity. Body mass index was not found to be a significant factor influencing adherence to treatment.