Changes in body composition in women using long-acting reversible contraception.

Area of Science:

• Reproductive Health
• Endocrinology
• Body Composition Analysis

Background:

• Hormonal long-acting reversible contraception (LARC) is frequently associated with user-reported weight gain.
• However, objective data on body composition changes among users of different LARC methods are limited.
• This study addresses the need for evidence-based information on LARC and body composition.

Purpose of the Study:

• To evaluate and compare changes in weight and body composition over 12 months in healthy women using three LARC methods: levonorgestrel intrauterine system (LNG-IUS), copper intrauterine device (IUD), and etonogestrel implant.
• To test the hypothesis that weight gain and body composition do not differ significantly between these LARC methods.

Main Methods:

• A prospective cohort study was conducted with women initiating LNG-IUS, copper IUD, or etonogestrel implant.
• Participants with no metabolic/eating disorders and stable weight (±5%) in the prior 6 months were included.
• Weight and body composition (body fat percentage, fat mass, lean mass, total body mass) were measured at baseline and after 12 months of continuous method use.

Main Results:

• Data from 149 participants (85 LNG-IUS, 31 copper IUD, 33 etonogestrel implant users) were analyzed.
• While lean body mass increased in LNG-IUS and copper IUD users but not etonogestrel implant users, overall changes in weight and body composition did not differ significantly between the groups.
• Black race was associated with a change in total body mass in the adjusted model.

Conclusions:

• Over 12 months of continuous use, no significant differences in weight or body composition changes were observed among users of copper IUD, LNG-IUS, and etonogestrel implant.
• These findings suggest that the choice of these LARC methods may not differentially impact body weight and composition in healthy women.