Snippet: Depo-provera and bone scans

Women using depot medroxyprogesterone (Depo-Provera) for longer than two years do not usually require bone scans

It is generally accepted that the use of Depo-Provera results in reduced bone mineral density (BMD). The reduction in bone mineral density occurs in the first two to three years of use and then stabilises.¹ This is of particular concern in young adolescent women who have not yet attained their peak bone mass, long term users and in older women who may be starting to lose bone mass.

In 2004 the UK Committee on the Safety of Medicines issued a warning regarding bone loss with Depo-Provera use and made the following recommendations:¹

• In adolescents, Depo-Provera should be used only when other methods of contraception are inappropriate.
• In all women, benefits of Depo-Provera beyond two years should be evaluated against risks.
• In women with risk factors for osteoporosis a method of contraception other than Depo-Provera should be considered.

The FDA also issued a similar "black box" warning in November 2004.²

A study showed that many people had interpreted this advice as a warning against using Depo-Provera for longer than two years,³ however this is not the case. Depo-Provera can be used for longer than two years, as long as the patient is regularly reviewed. There is some evidence that women who switch contraceptive methods tend to switch to a less effective one and possibly by restricting the use of Depo-Provera the number of unintended pregnancies could increase.³

Recommendations:

• There is evidence that bone mineral density recovers after discontinuation of Depo-Provera.⁵
• There is a lack of evidence that suggests the decrease in bone density is associated with increased risk of fracture.^{5, 6}
• Depo-Provera is useful in women who find it difficult to remember to take a pill every day or who are intolerant of oestrogen.⁷
• After counselling about the use of other contraceptives that do not reduce bone mineral density, the benefits of Depo-Provera in young people generally outweigh the risks.⁷
• More frequent follow-up may be appropriate for young people than adult contraceptive users.⁷
• Follow up of all Depo-Provera users at two years is recommended and should involve clinical history-taking, lifestyle assessment and a discussion of the balance between the benefits and potential risk, however bone scans are not routinely required.⁷