Early weight gain related to later weight gain in adolescents on depot medroxyprogesterone acetate.

OBJECTIVE: To examine whether early weight gain in adolescents on depot medroxyprogesterone acetate (DMPA) predicts continued excessive weight gain and identify risk factors of early weight gain.

METHODS: Adolescents (n=97) initiating DMPA were eligible to participate. Height and weight were assessed at baseline and at 6, 12, and 18 months. Early weight gain was defined as more than a 5% weight gain after 6 months of DMPA use. Mean body mass index (BMI) at 6-month intervals was estimated based on early weight-gain status (5% or less gain compared with greater than 5% gain). Analysis of variance modeling was used to compare group BMI at each time point. Repeated-measures analysis of covariance modeling was used to explore the association between early weight gain and percentage change in BMI at 12 and 18 months of DMPA use.

RESULTS: Twenty patients (21%) had early weight gain. Mean BMI for the 5% or less group and greater than 5% group was 23.4 and 24.5 (P=.31), 23.3 and 26.6 (P=.009), 24.2 and 28.7 (P=.007), and 25.7 and 32.1 (P=.01) at 0, 6, 12, and 18 months, respectively. Early weight gain was significantly associated with percentage change in BMI at 12 and 18 months (P<.001). No risk factors for early weight gain were identified.

CONCLUSION: Adolescents who experience more than 5% weight gain after 6 months of DMPA use are at risk for continued excessive weight gain. Weight gain after 6 months on DMPA can be used to identify adolescents at risk for continued weight gain, and appropriate counseling can be done at this time point.

LEVEL OF EVIDENCE: II.