Almost half of women who use birth control injections as a contraceptive will suffer a loss of bone density within two year, new research has suggested.
Researchers at the University of Texas Medical Branch in Galveston have said women who use depot medroxyprogesterone acetate (DMPA) will experience high bone mineral density (BMD) loss in the hip or lower spine.
According to the study, DMPA users who smoke, have low levels of calcium and are yet to have given birth are at the highest risk for BMD.
The researchers also discovered that women at high risk continued to experience significant losses in BMD during the third year of DMPA use, especially in the hip, which is the most common fracture site in elderly women.
Senior author Dr Abbey Berenson, professor in the department of obstetrics and gynaecology and director of the Centre for Interdisciplinary Research in Women's Health at the university, said: "Bone mineral density loss is not a significant concern for all women who choose DMPA.
"Based on these findings, clinicians have the information they need to recommend basic behaviour changes for high risk women to minimize BMD loss."
