Yes, it is possible to become pregnant with an IUD; however, this is extremely rare, occurring in less than 1% (one out of every 100) of women who use an IUD. If you do become pregnant, there is a higher chance that your pregnancy will be ectopic (occurring outside of the uterus) or you will develop complications with your pregnancy, if it continues.

How effective is an IUD?

No type of birth control is 100% effective, the only 100% effective method is abstinence (not having sex). IUDs have one of the highest rates of effectiveness at over 99%.

This is because once it is inserted, it protects from pregnancy 24 hours a day for every day of the year for up to 10 years. Once an IUD is in place, a woman does not have to remember to do anything else (such as take a daily pill) to ensure its effectiveness. IUDs will not protect against STD’s, only condoms do this to a certain extent.

Does effectiveness vary among the different IUDs?

Effectiveness does vary slightly among all the currently available IUDs; however, they all have an effectiveness rating of above 99% (this means that pregnancy will occur in less than 1% of women who have an IUD correctly inserted).

Good quality trials have reported the following:

• Paragard IUD: chances of pregnancy 0.8%
• Mirena IUD: chances of pregnancy 0.2%
• Skyla IUD: chances of pregnancy 0.4%
• Copper T 380A: chances of pregnancy 0.6%
• LNG-IUC: chances of pregnancy 0.2%.

Is there a risk of ectopic pregnancy with an IUD?

Using an IUD puts you at a higher risk of ectopic pregnancies than pregnancy in the general population. Research has shown that the incidence of ectopic pregnancy with Paragard was 0.06% (6 women out of every 10,000 who use Paragard) and the incidence of ectopic pregnancy with Mirena and Skyla was 0.1% (1 woman out of every 1000 who use Mirena or Skyla).

Ectopic pregnancies are pregnancies that occur outside of the uterus, usually in the fallopian tubes. An ectopic pregnancy can't proceed normally because the fertilized egg cannot survive if it is not in the uterus. In addition, if the embryo is left to develop, the growing tissue may cause life-threatening bleeding. If you develop an ectopic pregnancy while Paragard, Mirena, or Skyla is inserted, you may require surgery.

What happens if you do become pregnant while an IUD is inserted?

If you do become pregnant with an IUD in place, and the egg has implanted itself in the lining of your uterus, then you are at an increased risk of miscarriage, sepsis, premature labor, and premature delivery.

You should go to your doctor straight away and get the IUD removed if the strings are visible or can be retrieved; however, the success of this depends on how far along your pregnancy already is. Research has shown the risk of miscarriage is up to 27% when the IUD was removed compared with 77% if the IUD was left in place.

Leaving an IUD in place if you become pregnant increases your risk of spontaneous abortion, septic abortion, septicemia, septic shock, premature labor, premature delivery, a hysterectomy or permanent infertility, or death.

If an IUD cannot be removed or if you choose not to have it removed, you will need to monitor yourself and report immediately to your doctor any flu-like symptoms, fever, chills, cramping, pain, bleeding, vaginal discharge, or leakage of fluid, or any other symptom that suggests complications of the pregnancy.

Women who are already pregnant should not have an IUD inserted because it may cause adverse pregnancy outcomes.