Comparison of weight gain between levonorgestrel and etonogestrel implants after 12 months of insertion

Objective: To compare weight gain between women using etonogestrel implants and those using levonorgestrel implants 12 months after insertion.

Methods: A multicenter prospective cohort study was performed on women recruited from family planning clinics between July 2016 and August 2017. The main study outcome was mean weight gain after 12 months of insertion of the implants.

Results: The present study included 150 women (age range 18-45 years) using levonorgestrel implants and 167 women using etonogestrel implants. The women recruited had been using implants for less than 6 months; implants had been inserted 6-12 months after their last pregnancy. Participants were followed up until 12 months after insertion through telephone conversations. Baseline parameters were obtained from the clinic records and weight was measured within 6 weeks of the 12-month anniversary of insertion of the implants. Data were analyzed with SPSS version 23. Weight gain in the levonorgestrel group was significantly higher than in the etonogestrel group (3.16 ± 4.08 vs 0.77 ± 3.76, P = 0.013; relative risk 1.69, 95% confidence interval 1.46-1.96). There were no differences in the occurrence of menstrual irregularities and client satisfaction.

Conclusion: Women using levonorgestrel implants were more likely to gain weight compared to those using etonogestrel implants after 12 months of insertion.