Bone mineral density during long-term use of the progestagen contraceptive implant Implanon compared to a non-hormonal method of contraception.

An open, prospective, comparative study was done in healthy women, aged between 18 and 40 years, to study the effects of long-term etonogestrel treatment on bone mineral density (BMD). The control group used a non-hormone-medicated intrauterine device (IUD). The BMD was measured using a dual energy X-ray absorptiometry instrument. Measurements included the lumbar spine (L(2)-L(4)), the proximal femur (femoral neck, Ward's triangle, trochanter) and distal radius. The period of treatment was 2 years and 44 women in the Implanon group and 29 in the IUD group provided data. Groups were comparable at baseline with respect to age, weight, body mass index, BMD and 17beta-oestradiol status. Changes from baseline in BMD in the Implanon group were not essentially different from those in the IUD group. There was no relationship between 17beta-oestradiol concentrations and changes in BMD in this study population. The results of the present study indicate that Implanon((R)) can safely be used in young women who have not yet achieved their peak bone mass.