Thyroid function during the first year of use of the injectable contraceptive depot medroxyprogesterone acetate.

The aim of the study was to evaluate thyroid function profile as a possible factor influencing weight and body composition variation in new users of depot medroxyprogesterone acetate (DMPA). A prospective, non-randomised, comparative study was conducted at the University of Campinas, Brazil. Women aged 18-40 years with a body mass index (BMI) less than 30 kg/m We evaluated 28 DMPA users and 24 IUD users who completed the 12-month follow-up. We observed that FT4 levels were higher at 12 months (compared to baseline) in the DMPA group (p < .0001) and that FT4/FT3 ratio had increased in both groups. Additionally, at 12 months, total body mass had increased around 2 kg and lean mass increased in the DMPA group compared to the IUD group; there was also an increase in weight, BMI, total body mass, and fat mass when compared to baseline. No changes in thyroid function occurred that could explain the weight increase observed in DMPA users.