Intrauterine Device (IUD)
IUDs are inserted by a doctor through the vagina and cervix, into the uterus.
Most are made of molded plastic and have a string that you can feel in the vagina.
IUDs currently available in the Canada do not increase a woman's risk of ectopic
pregnancy, infertility, or infection.
Two IUDs are currently available:
- Copper-containing IUD (Nova-T, Flexi-T) prevents pregnancy
by preventing sperm from reaching the fallopian tubes. Copper-
containing IUDs last for up to 5 years. Some women who use a
copper-containing IUD have heavier and longer menstrual periods.
Flexi-T comes in two "sizes" (300 and 380) the 300 is preferred
for women who have not had children.
- Levonorgestrel-releasing IUD (Mirena®) prevents pregnancy by
thickening the cervical mucus and thinning the endometrium
(the lining of the uterus).
- It also decreases menstrual bleeding by 40 to 90 percent and decreases
pain associated with periods. It can be left in place for up to 5 years, and is
highly effective in preventing pregnancy.
- Some women completely stop having menstrual periods while using a
levonorgestrel-releasing IUD. This is not harmful and does not require treatment.
Menstrual periods will return when the IUD is removed.
An IUD is an ideal method if you do not plan to become pregnant for at least one year (or longer) or you want a method that is highly effective and does not require daily or weekly attention. IUDs are also appropriate for women who do not want to or cannot use estrogen.
IUDs have relatively few side effects, and are reversible. If you decide you want to become pregnant, you can do so by having the IUD removed. IUDs do not affect your chance of becoming pregnant after the IUD is removed.
You should check your IUD once per month, after your menstrual period, by finding the strings inside the vagina. There is a small risk that the IUD will come out during your period. If you cannot feel the strings, use a backup method (eg, condoms) until you can see a doctor or nurse to be sure the IUD is still there.
You should not use an IUD if you have undiagnosed genital tract bleeding, recently had a pelvic infection such as gonorrhea or chlamydia or immunosuppressed condition. If you have more than one sex partner, talk to your doctor or nurse about the risks and benefits of the IUD.
Copper IUD’s are contraindicated if you have a Wilson’s disease.
If you become pregnant while using an IUD, you need an ultrasound to be sure that the pregnancy is inside the uterus, rather than in the fallopian tube (called an ectopic pregnancy). The IUD should be removed when the pregnancy is discovered.