I’m not sure where some of the GYNO myths start, but according to my colleagues, there are a lot of questions circulating about the safety of the copper IUD with respect to copper in the blood stream.
“Will my copper IUD affect copper levels in my blood” is a reasonable question, especially knowing that individuals with Wilson’s disease, a disorder of copper metabolism, develop serious and irreversible neurological and liver problems from excessive copper deposits in the tissues.
Several studies from the 80’s and 90’s have looked at the issue (nothing recent because copper IUDs have been around for a long time).
What the science tells us is there is a local increase in copper levels in the lining of the uterus and in the fallopian tubes (meaning the copper IUD releases copper). That makes sense as copper affects sperm capacitation, a step the sperm need to complete so they can penetrate the egg). Therefore, for the copper IUD to work the copper has to reach the area of the reproductive tract where fertilization happens (typically the fallopian tube). However, in these studies there was no change in copper levels in the blood. One study also looked at level of ceruloplasmin, the protein that carriers copper in the blood, and it stayed the same as well. (1) If excessive copper were getting into the blood, the body would also make more ceruloplasmin to compensate.
Regardless, if you have Wilson’s disease, you should not have a copper IUD. However, for everyone else, the copper IUD does not affect copper levels in the blood.
Myth busted. The copper IUD really is 10 years of worry free contraception.
1) Wollen AL et al. The localization and concentration of copper in the fallopian tube of women with or without an intrauterine copper device. Acta Obstet Gynecol Scand 1994;73:195-9.