Emergency Contraception: the Copper-T IUD
The copper IUD is a great option for some women who need emergency contraception. It has a very low failure rate (less than 1%), making it the most effective form of emergency contraception available in the United States. Another benefit is that it can be inserted up to five days after intercourse. The IUD is only recommended for women who are at a low risk for sexually transmitted diseases and pelvic inflammatory disease, and it is best if the woman has given birth before and does not have a history of ectopic pregnancy.
For more general information on IUDs, click here
Paraphrased from:
Crooks, Robert and Baur, Karla (2002). Our Sexuality, 317-318.