BACKGROUND: Weight gain is a frequent reason for discontinuing the contraceptive with depot-medroxyprogesterone acetate (DMPA). STUDY DESIGN: This 3-year retrospective cohort study assessed body mass index (BMI; kg/m(2)) variations in 379 current or past DMPA users compared to TCu380A intrauterine device (IUD) users matched for age and BMI, categorized into G1 (normal weight), G2 (overweight) or G3 (obese) according to baseline BMI. Variations in weight and BMI were evaluated using analysis of variance. RESULTS: BMI increased progressively in all groups but significantly more in G1 and G2 DMPA users compared to nonusers and according to duration of use. In the G3 subgroup, weight trends were similar in the DMPA and IUD users. CONCLUSIONS: Normal and overweight women increased BMI with DMPA use; however, obese women did not increase weight. Weight increase in DMPA users could be associated with metabolic alterations related to duration of use in normal and overweight women and to alterations already present in obese women. Prospective studies are required to determine triggering factors. DMPA use or=30.