Intrauterine system, levonorgestrel

Mirena, A New Method Of Contraception

 By Dr. Gifford Jones

Wouldn’t all women like to stop worrying about birth control for five years? Not to have to remember to take the pill every day. Or face the bother of having to insert a vaginal contraceptive each time before sex. Now, a new unique intrauterine system, Mirena, which has been used in Europe for over 10 years, is available in Canada.

Why has it taken so long for Mirena to get here? In the 1960s IUDs became quite popular. But one IUD, the Dalkon Shield, triggered complications due to a faulty design. This resulted in a U.S. class action law suit. It’s producer failed, and all the other IUDs in the U.S. were pulled from the market. Greedy lawyers and greedy patients, looking for an easy million, were largely to blame for a good contraceptive going down the drain. 

In Canada, doctors have prescribed IUDs for years. In fact, few realize that worldwide the intrauterine device is the most commonly used form of reversible contraception.

Mirena is the same design as other IUDs with one big difference. The T-shaped frame is surrounded by a narrow cylindrical reservoir that contains levonorgestrel. This hormone, commonly used in birth control pills, is similar to progesterone, a sex hormone produced by the body. Two fine plastic threads are attached to the device which are needed for removal and to confirm its presence after being placed inside the uterus.

Mirena works by slowly releasing tiny amounts of levonorgestrel into the uterus each day for the next five years. It prevents pregnancy by decreasing the thickness of the lining of the uterus. But it also increases the thickness of cervical mucus which in turn blocks sperm from entering the uterus. Studies show that Mirena is equally as effective as oral contraceptives or sterilization.

The best time to insert Mirena is during the menstrual period. The Mirena system, which is about the size of a piece of spaghetti, is gently placed inside the uterus. Some women complain of minor discomfort following insertion which disappears in a few days. And once inserted, the patient is immediately protected from pregnancy for the next five years.

For most women Mirena offers the benefit of shorter, lighter periods. Some women notice that their period stops immediately. Others may see this happen over time. And many notice less menstrual pain. But during the first three to six months patients may experience unpredictable spotting or bleeding in addition to menstrual periods. In some cases there may be heavy or prolonged bleeding.

Following insertion a few women suffer from mild headache, breast tenderness, nausea or depression. But these effects normally subside over a period of time.

Remember, Mirena will not protect women from sexually transmitted disease. Unfortunately, in the past some have complained that IUDs caused infection. But studies show that it’s a woman’s dangerous lifestyle with multiple sexual partners that result in infection, not the IUD.

Mirena isn’t for all women. It’s not advisable for those who have had pelvic infection, a stroke, heart attack, a history of blood clots or a previous tubal pregnancy. And if pregnancy occurs, a rare possibility, the system must be removed.

Today women have a variety of contraceptive methods from which to choose. They are more effective, convenient and safer than at any other time. Unfortunately some women play Russian roulette carelessly neglecting to take any form of birth control. The result is unwanted pregnancy. Mirena is ideal for these women or those who frequently forget to take the birth control pill.

So who is the perfect patient for Mirena? It’s ideal for the working woman who wants to space her family every three to five years. The system can be inserted six weeks following a delivery. I have also found it to be a good alternative for patients who are smokers and unable to take oral contraceptives. And ovarian function and fertility are normally rapidly restored after removal of the system.

Since Mirena often offers the benefit of shorter lighter periods it may offer an alternative to hysterectomy for women suffering from excessive bleeding.

W. Gifford-Jones M.D is the pen name of Dr. Ken Walker graduate of The Harvard Medical School. He’s been a ship’s surgeon, hotel physician and family doctor and later trained in surgery at McGill in Montreal, University of Rochester N.Y. and Harvard. His medical column is published by 60 Canadian newspapers and several in the U.S. He is the author of seven books. Dr. Walker has a medical practice in Toronto. His Web site is: http://www.mydoctor.ca/gifford-jones. He can be reached at

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Dr. Gifford Jones  Bio

Dr. Gifford Jones Most recent columns W. Gifford-Jones M.D is the pen name of Dr. Ken Walker graduate of The Harvard Medical School. He’s been a ship’s surgeon, hotel physician and family doctor and later trained in surgery at McGill in Montreal, University of Rochester N.Y. and Harvard. His medical column is published by 60 Canadian newspapers and several in the U.S. He is the author of seven books. Dr. Walker has a medical practice in Toronto. His Web site is: http://www.mydoctor.ca/gifford-jones. He can be reached at: