Mirena, known by its generic name levonorgestrel, is an IUD with progesterone contraception currently marketed by Bayer. It is a hormonal, long-acting, and reversible birth control device that is also used for managing menorrhagia (intense periods), anemia, dysmenorrheal, and preventing certain diseases like uterine fibroids and adenomyosis. After IUD placement, an initial 20 micrograms of levonorgestrel is released directly into the uterine lining, which decreases ovulation frequency, thickens cervical mucus to serve as natural barrier, and triggers the uterus to unleash a stream of prostaglandins and leukocytes that can kill sperm and egg cells.

Efficacy

In several comparative and non-comparative studies, the cumulative probability of pregnancy with Mirena is as little as one pregnancy in every 100 women for the use of Mirena IUD as compared to other non-hormonal IUD products. One trial has established 0-0.2% pregnancy rate for a one year study and 0.5-1.1% for studies that lasted for at least five years. This does not mean, however, that it is 100% effective compared to other competing birth control products as comparative studies show otherwise.

Side Effects

It has been reported that some Mirena users are experiencing symptoms of pregnancy with Mirena. Some claim that their breasts became tender, and they felt as if they were lactating. Other users verbalized that they have experienced increased urinary frequency, morning sickness, and developed cravings for certain food types. Other accompanying symptoms were the feeling of a bloated abdomen or stomach, frequent low back pain, dizziness, and even vomiting on some occasions.

Clinical tests show that for the initial 3-6 months, monthly periods may be irregular and the incidence of periods may seem to increase. Spotting and slight vaginal bleeding may be evident in the first months as well. But later on, the periods may eventually stop for the duration that the IUD is in place (temporary amenorrhea). This is probably one of the reasons why Mirena users sometimes think they have become pregnant because missing menstrual periods will become a normal occurrence. Other symptoms that are listed as probable side effects of Mirena use include:

  • Dizziness, headache, and migraine
  • Nausea
  • Abdominal pain
  • Acne development
  • Mood swings or mood alterations (i.e., frequently depressed)
  • Back pain
  • Breast tenderness

As you can see, these symptoms are usually present during pregnancy. But these symptoms of pregnancy with Mirena normally occur during the first months of IUD use.

Safety

There are already a lot of studies conducted to test the safety of Mirena as compared to other methods of contraception like Cu-IUDs. The majority established that:

  • Mirena use does not lead to weight gain.
  • There is low risk of pelvic inflammatory disease and breast cancer development.
  • There is low Mirena pregnancy incidence, specifically ectopic pregnancy.
  • Mirena use has been observed to improve hemoglobin, serum protein, and serum ferritin levels.

Although Mirena has been noted to be safe and very effective for use, it must be replaced with a new set every five years. You can still use tampons if you're using this device.

References
  1. Mirena: Efficacy and safety . http://www.mirena.com/en/professional/contraception/efficacy_and_safety/index.php
  2. IUD with progestogen . http://en.wikipedia.org/wiki/IUD_with_progestogen
  3. Mirena. http://www.pdrhealth.com/drugs/mirena
  4. Mirena Drug Center. http://www.rxlist.com/mirena-drug-center.htm
  5. Mirena. http://www.centerwatch.com/drug-information/fda-approvals/drug-details.aspx?DrugID=662
Discussions(8) Add New
  1. Oszl September 21, 2011 01:53 PM Reply

    Mirena is a good solution if you do not want to have baby. But everything can have some side effects. It can increase your weight. It can effect on your mood. Moreover, the periodical cycle comes after passing many months. So, an increase in weight or delay in periods does not mean that you are pregnant. Pregnancy symptoms with marina varies in different cases.You can check your pregnancy through strip or urine test. s

  2. Adelbert September 28, 2011 01:13 PM Reply

    My case is a bit different. I have used mirena for 5 years. First, I had experienced that my periods were getting lighter. After some time, periods come after 2 or three months. At the end, I used to have periods twice in a year. It was not due to pregnancy. I was due to mirena. I enjoyed that time. Now I have changed the old mirena and have got new one. For the last two months my periods are regular. I am feeling pain as well. There are a few chances of pregnancy with mirena.

  3. Sitembile January 03, 2012 12:22 AM Reply

    Hi to all, I have the same problem as is discussed by others. But the thing that is making me worried is that I am getting weight. My belly is getting bigger in size. My breast is also increasing in size. Is it due to mirena or is it due to pregnancy? I am not sure about it. I have made home tests as well. The result is always negative. I do feel the morning sickness. Please tell me is there any possibility to get pregnant with mirena?

  4. Olin January 10, 2012 05:25 PM Reply

    I am not sure about the pregnancy with mirena. I think you can have one percent pregnancy risk while using such type of coils. It is really a safe way. It helped me in making my cycle regular. Now, I have no fear of spotting or excess of bleeding. I can ride as long as I want. I can wear my lovely swimming suit as well. Yeah, it can cause some side effects like headache, low desire for sex or pain.

  5. Papillon April 21, 2012 02:27 PM Reply

    The thing, which I know about mirena is that it should remain at its exact place. It makes the mucous near the womb so thick that sperms cannot travel through it. So, mirena eliminates the chances of pregnancy. When mirena shifts from its place usually due to intercourse then there can be the risk of pregnancy. Wait for your menstrual cycle if it does not occur then go to your doctor.

  6. Lia May 04, 2012 07:45 AM Reply

    I am also facing the same problem. I have been using the mirena for the last 4 years. I did get pregnant. But this time, sudden changes are occurring in myself. I feel the morning sickness. At daytime, I get hungry and want to eat salty foods. My weight is also getting increased. I have checked for the pregnancy at home. But the result is negative. I am not sure about myself whether I am pregnant or not? Please tell me the rate of pregnancy with mirena?

  7. Sabine June 20, 2012 01:52 PM Reply

    Hi, it's true that after inserting mirena change in periods does occur. You can feel more bleeding and more pain. But after some time, everything gets normal. But I am not sure about the pregnancy with mirena. I have used the mirena for three years and I could not get pregnant for that time.

  8. Easter July 07, 2012 06:04 AM Reply

    Friends, I want to get the answer of my problem. I was experiencing severe periods for one year. I was fed up with pain and exercise used to make me bleed. I was told to have mirena. First, I experienced severe pain and excess of bleeding. But after two months, my periods got lighter. This time my periods have got late. Is it due to pregnancy with mirena?