Weight change in adolescents who used hormonal contraception

Purpose: (a) To compare weight change at 1 year between adolescents 13-19 y ears old who were using either depot medroxyprogesterone acetate (DMPA) or oral contraceptives (OC), and (b) to determine if age, baseline body mass i ndex (BMI), race/ethnicity, or weight gain at 3 months predicted which subj ects would gain excessive weight. Method: The setting was a Planned Parenth ood Teen Clinic with chart review of variables of interest. Excessive weigh t was defined as weight gain > 10%. Results: Baseline variables were simila r in the two groups, except that DMPA users (n = 44) had a greater mean BMI (t test, p = .05) than OC users (n = 86). Mean (standard deviation) and me dian weight gains at 1 year were 3.0 (4.5) and 2.4 kg in the DMPA users and 1.3 (3.9) and 1.5 kg in the OC users (difference in medians not significan t, Wilcoxon rank sum test, p = .10). Fifty-six percent of DMPA and 70% of O C users lost weight or gained < 5% of their baseline weight (p = .17, Fishe r exact test); 25% of DMPA users and 7% of OC users gained > 10% of their b aseline weight (p = .006). Age, baseline BMI, or race/ethnicity did not aff ect the likelihood that either group would gain > 5% or > 10% of their base line weight. Of adolescents who gained > 5% of baseline weight at 3 months, 13 of 14 (93%) gained even more weight at 12 months. Conclusions: The majo rity of adolescents who used hormonal contraception for 1 year lost weight or gained < 5% of baseline weight. DMPA users were more likely than OC user s to gain > 10%. Subjects who gained > 5% of baseline weight at 3 months we re at high risk (93%) of gaining even more weight by I year. (C) Society fo r Adolescent Medicine, 1999.