What's all the hype about the Mirena® IUD?

Mirena® provides over 99% contraceptive efficacy. Mirena® is a relatively new IUD, (Intrauterine Device), with the stem of the IUD impregnated with levonorgestrel, the progestin hormone found in many birth control pills. It is an extremely effective, very low maintenance, long lasting form of birth control. Once inserted, it is immediately effective, and lasts for 5 years. It is ideal for insertion when breast feeding, avoiding most of the initial side effects.

What side effects?
Well, Mirena® has the potential to completely eliminate your periods. This is accomplished by the high hormone concentrations in the uterus itself. The lining of the uterus gradually thins to the point that it no longer bleeds. The thinning of the lining is accomplished by bleeding it down to its thinnest possible thickness. When you are breast feeding the lining is already thin, and the "break in" time is very short. If you are not breast feeding, the bleed down period can be two to three months.

What does that mean?
Well, you may bleed irregularly for two to three months. Sounds terrible. However, this is similar to what can happen with other hormonal methods such as birth control pills or deprovera (the shot). Once you get through this time, many women will have either very light periods or no periods at all!

Is that healthy?
Yes. Bleeding represents failure to conceive, and the body preparing for the next cycle, attempting to conceive again. The bleeding with your period is not cleansing the uterus, and the lost blood wastes iron from your body. Imagine.... 5 years with no periods. Your ovaries continue to make your normal hormones, but the strong effect of the IUD directly on the uterus prevents bleeding.

How likely am I to really have no periods?
Most women will have only very light occasional bleeding. This is more likely if you are relatively thin. Heavier women make more estrogen, and are less likely to have complete absence of periods.

Doesn't this sound too good to be true?
It may be too much to expect. Some women will have pain from the presence of the IUD, which is a foreign body in the uterus. If you have exposure to more than one sexual partner, the risk of infection in the uterus and tubes may be increased.

Women with Bacterial Vaginosis (see "What is Bacterial Vaginosis?") may have more problems with bleeding and pain. A serious infection could make it harder for you to get pregnant. If you get pregnant with the IUD in place, you are more likely to have a tubal pregnancy.

Some women will absorb enough of the hormone from the IUD to have mild side effects such as oily skin or acne, breast tenderness, or moodiness. Sometimes the irregular bleeding persists and women just give up on the IUD.

Removal of the IUD, like insertion, is short office procedure performed through a speculum, like a pap smear. The insertion can cause painful cramping, so it is good to take ibuprofen prior to coming in for insertion. If you are not breast feeding, the IUD is inserted while you are on your period. Fertility returns immediately after removal of the Mirena®, unlike the shot, which may take up to one year to return to normal.

In summary, the Mirena® IUD is not a perfect product, it takes a commitment to the method to get through the initial break in time. But if you are the right candidate, and you make it through the first 3 months, it can be a life changing method. Freedom from pregnancy, nothing to remember to do each day, and hopefully, few if any periods. You may want to visit Mirena's website for more information.

Dr. Paul Daum, M.D. Provides Complete OB/GYN Services

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