Contraception

Contraceptive Methods

Intra-uterine System (Mirena)

The intra-uterine system (IUS) provides reliable, reversible contraception for up to five years. This hormonal method of contraception is more than 99% effective in preventing pregnancy.

How does it work?

The IUS is made up of a small T-shaped frame with a small cylinder containing the hormone levonorgestrel. It does not contain estrogen. This cylinder slowly releases the hormone that acts on the lining of the uterus. The lining of the uterus becomes thinner and the cervical mucus becomes thicker which makes it harder for sperm to enter the uterus.

Benefits

The IUS does not contain estrogen so it can be used in women who cannot take or have a sensitivity to estrogen. The IUS is effective for up to five years. Unlike the copper intra-uterine device (IUD), the IUS decreases the amount of menstrual bleeding and may decrease menstrual cramping.

Disadvantages

The hormonal IUS does not protect against sexually transmitted infections (STIs) or HIV. Condoms should be used to protect against STIs or HIV.

Complications associated with the IUS are rare but may occur. Possible complications of inserting an IUS include irregular bleeding or spotting, perforating the uterus (making a small hole in the uterus), infection, or expulsion (the IUS falls out).

Side-Effects

• Irregular bleeding or spotting
  This is most common within the first 3 months following insertion. It usually improves with time.
• No periods (amenorrhea)
  Most women that use the IUS notice that their periods are less heavy. Of women that are using the IUS, 20-30% of women will stop having periods (amenorrhea). Not having a period does not necessarily mean that you are pregnant but it may just be a side-effect of the IUS.

Myths and Facts

1. MYTH: The IUS cannot be used by someone who hasn't had a baby before.
   FACT: The IUS can be used by women who have not had a baby.

2. MYTH: The IUS increases the risk of infertility.
   FACT: IUSs do not increase the risk of infertility. Women who have their IUS taken out because they want to get pregnant will get pregnant at the same rate as women who have never used an IUS.

3. MYTH: IUSs increase the long-term risk of infection (pelvic inflammatory disease).
   FACT: After the first month of use, the risk of infection is not significantly higher than in women without IUSs.

4. MYTH: The IUS increases the risk of having an ectopic pregnancy (a pregnancy in the fallopian tubes)
   FACT: The IUS does not increase the risk of ectopic pregnancy.

How to use the IUS

You will need a prescription to get the IUS from the pharmacy. A health care provider must insert the IUS, usually in the office. Your health care provider will insert the IUS into the uterus through the cervix (opening of the uterus). The IUS can be inserted at any time during the menstrual cycle as long as pregnancy can be ruled out. If you have already an IUS inserted, it can be removed and a new one inserted on the same day. It takes only a few minutes to insert an IUS. You may feel some cramping pain when the IUS is being inserted. You may be given a local anesthetic or pain medicine to help control discomfort during insertion.

You should check for the IUS strings from time to time to make sure that the IUS is still in the uterus. You can do this by putting a finger inside the vagina and feeling for the strings near the cervix.

You should contact your health care provider if any of the following occur:

• You cannot feel the IUS threads
• You or your partner can feel the lower end of the IUS
• You think that you are pregnant
• You experience persistent abdominal pain, fever, or unusual vaginal discharge
• You or your partner feel pain or discomfort during intercourse
• You experience a sudden change in her menstrual periods
• You wish to have the device removed or you want to get pregnant.

Last Modified: September 5, 2006

FAQS

sexualityandu's Frequently Asked Questions about the Intrauterine System