[afro-nets] Resources on community-based distribution of Depo-Provera (DMPA)(4)

["David Hock" <DHock@fhi.org>]

Resources on community-based distribution of Depo-Provera (DMPA)(3)
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Posted on behalf of Irina Yacobson, Assistant Medical Director at FHI:

Dear readers,

I read with interest Rougui Diallo's posting on use of injectable contraception. Below, I am appending a summary of the scientific evidence on her question, from the Injectables Toolkit website posted by Johns Hopkins University at http://www.infoforhealth.org/injectables/.
What may be helpful to point out here is that some women do have osteoporosis regardless of whether they use Depo Provera (DMPA), and some of those who have osteoporosis do also take depo. This doesn't mean that there is a causal relationship between the two. There are many, many women in the United States on DMPA and the evidence does not indicate that they experience any effects related to bone loss.

The question of whether use of injectable contraception leads to bone loss has been studied extensively, over many years. There are no new data regarding bone density and no new studies are currently being conducted. The bottom line from available evidence is: women who use
DMPA for 2-3 years don't lose bone at all. Those who are younger than 45 regain bone density after stopping use of DMPA no matter how long they used it. The only question, based on theoretical risk, is how use of DMPA affects young adolescents (below 18) and women who are approaching menopause, or those who are older than 45 (they may not have enough time to gain their bone back, as estrogen levels drop during menopause).

The World Health Organization has concluded that the benefits of very reliable protection from pregnancy outweigh theoretical risks of bone loss. (See their statement at
http://www.who.int/reproductive-health/family_planning/bone_health.html)
 Below is some relevant text from the Injectables Toolkit, as well as a Question and Answer sheet on this topic, published in Jim Shelton's series of "Pearls" in 2005.

Best regards,

Irina Yacobson, MD
Assistant Medical Director
Family Health International
PO Box 13950
Research Triangle Park, NC 27709 USA
Email: news@fhi.org

(From the Injectables Toolkit:) Why does DMPA affect bone density?

DMPA reduces levels of estrogen in the body. Estrogen helps to regulate the flow of minerals to and from the bones. When estrogen levels are low, more minerals are lost from bone than are reabsorbed. This leads to a decrease in bone density (137).

Whether DMPA increases the risk of broken bones requires more research. A woman's lifetime risk of broken bones is unlikely to be affected because women regain bone density after stopping DMPA. Among adults who stop using DMPA, after two to three years their bone density appears to be similar to that of women who have not used DMPA. Among adolescents, it is not clear whether the loss in bone density prevents them from reaching their potential peak bone mass. Also, more research is needed on the effect of DMPA use during the reproductive years on the risk of broken bones during menopause, and the effect of DMPA use near menopause on a woman's ability to regain lost bone density.

Because of the bone loss issue, drug regulatory agencies in the United Kingdom and United States advise women to consult providers after using DMPA for two years to decide if they want to continue DMPA or to choose another method (49, 193). An expert working group advising the World Health Organization, however, concluded that the decrease in bone density should not limit who uses DMPA, or for how long, among women ages 18 to 45. The benefits of using DMPA outweigh the theoretical concerns about bone fracture for these women and for adolescents younger than 18 and women over 45. Since there is not enough information about long-term DMPA use by adolescents and women over 45, the expert group recommended that providers and these women reconsider the benefits of DMPA and their risk of bone fracture over time. These recommendations also apply to NET-EN (216).

(From Jim Shelton's Pearls at
http://www.jhuccp.org/pearls/pearl.php?id=313)
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PEARL
July 19, 2005
Injectable progestin-only contraceptives and bone density

Q: I understand that WHO recently convened a scientific review of injectable progestin contraceptives (such as DMPA) and reduced bone density. Can you tell me the result?

A: Yes. Clearly there is a legitimate concern because such progestin-only injectables do reduce bone density over time, in all likelihood because they largely suppress the ovaries' natural estrogen production (without replacement with another estrogen as combined oral contraceptives do.) These effects are relatively modest and appear to be largely if not completely reversible. Still there is specific concern about very young women who may not have achieved peak bone mass and older women nearing the menopause.

The WHO expert group examined the current evidence in depth, weighed the risks and benefits and issued the following recommendation:

There should be no restriction on the use of DMPA, including no restriction on duration of use, among women aged 18 to 45 who are otherwise eligible to use the method.

Among adolescents (menarche to <18) and women over 45, the advantages of using DMPA generally outweigh the theoretical safety concerns regarding fracture risk. Since data are insufficient to determine if this is the case with long-term use among these age groups, the overall risks and benefits for continuing use of the method should be reconsidered over time with the individual user.

Recommendations regarding DMPA use also pertain to use of NET-EN.

Thus the WHO position is fairly reassuring and in essence consistent with current WHO eligibility recommendations of a Category 1 for women 18 to 45 (use in any circumstances) and Category 2 for women less than 18 and over 45 (generally use), although for the latter group recommending some ongoing reconsideration with the client over time for long-term use.

References:
URL for the entire document:
http://www.who.int/reproductive-health/family_planning/bone_health.html

--
David Hock
mailto:DHock@fhi.org