Common Questions
When is it recommended to obtain a DEXA study on an adolescent or woman using DMPA?
Currently, it is not recommended to obtain a DEXA scan before initiating DMPA or during treatment.
The presence of one or more risk factors for low bone density may influence the provider's decision to initiate DMPA or monitor bone density with a DEXA scan in those who are on DMPA. The time frame for testing bone density is unknown but should likely be no earlier than two years after the initiation of DMPA.
Known risk factors for diminished bone density include Body Mass Index (BMI) < 16, anorexia, immobility, renal disease, cystic fibrosis, hyperthyroidism, malabsorption, previous estrogen deficiency, prolonged corticosteroid or immunosuppressant use, amenorrhea, excessive exercise, eating disorder, and family history.
In adolescents, it is important to remember to use Z-scores rather then the T-score to monitor bone density. The Z-score is the number of standard deviations below an average person of the same age, race and gender. The T-score is the number of standard deviations below the average for a young adult at peak bone mass. Adolescents have not yet reached peak bone mass. There are no established criteria to assess what amount of bone loss in the adolescent female is concerning. However, currently a Z-score of less > -2 is considered low bone density (1).
- Position Paper. Depot Medroxyprogesterone Acetate and Bone Mineral Density in Adolescents-The Black Box Warning: A Position Paper of the Society for Adolescent Medicine. J Adoles Health 2006; 39: 296-301.