Who should not use a copper IUD?

The copper IUD is a very effective form of birth control, however some women should not use it.  If you have a copper allergy (Wilson's Disease), for example.  Also women with undiagnosed abnormal bleeding, any chance of pregnancy, or any infections or sexually transmitted diseases should not have an IUD placed.  Women whose uteri have an abnormal shape or size may not be able to use an IUD either; this could be caused by large fibroids for example.  It is important to remember that an IUD will not protect you from sexually transmitted infections, so screening for STIs regularly is very important and a barrier method (condoms for example) should always be used.