Birth Control Pills May Reduce Bone Density

As a woman with PCOS, you may think that birth control pills are a benign, completely safe, highly effective pharmaceutical product that you can safely consume for as long as you like. However, no pharmaceutical, including birth control pills, can be taken with impunity.

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It's always a good idea to be clear on the benefits and risks of taking even the most benign and "safe" drugs. A case in point is a report from the Group Health Cooperative in Seattle. They said that oral contraception may decrease bone density in young women.

Those taking birth control pills for more than two years, and those on the low-dose estrogen pills appear to have the greatest risk of decreased bone density in the spine and whole body, according to the researchers. The study consisted of 606 women between the ages of 14 and 30. The researchers reviewed oral contraceptive use, the duration of use and the estrogen dose in the contraception, and compared this to bone mineral density tests. The bone density test measured bone density in the hip, spine and whole body.

When the researchers compared oral contraceptive users to non-users, they found that women taking oral contraception had average bone mineral density levels that were 5.9% less for the spine and 2.3% lower for the whole body. The researchers also noted a trend toward lower bone density in women taking oral contraceptives containing lower doses of estrogen, with the lowest readings in women taking formulations containing less than 30 micrograms of estrogen.

It's not entirely clear to what you may resume bone building at a normal rate once you have quit birth control pills. It depends to some extent on your age. Your prime bone-building years are in your teens and twenties. As you get older, your ability to build strong bones declines.

Why It's a Serious Issue for PCOS

The reduced bone density resulting from certain oral contraceptives is a serious issue because so many women with PCOS take birth control pills for a very long time. One of the Group Health researchers said that a 5% lower bone density after menopause is associated with a 50% increased risk of bone fractures from osteoporosis. Osteoporosis is a loss of bone density or mass that results in porous, brittle bones. It can be a disfiguring and painful disorder with no easy cure. The best cure for osteoporosis is prevention.

If you are on birth control pills for PCOS and are beyond your teen years, we recommend that you consult with your doctor about the type of pills you are taking and how much longer you should be taking them.

Source: Scholes D et al, Oral contraceptive use and bone density in adolescent and young adult women, Contraception. 2010 Jan;81(1):35-40