The Dalkon Shield was a contraceptive intrauterine device (IUD) that was marketed in the 1970s and was later linked with serious health complications. Due to its controversial history, it's important to know the various synonyms for the term. Some of the alternative names include Copper-7 IUD, progesterone IUS, Copper T IUD and Mirena. These devices are inserted into a woman's uterus for birth control purposes and function by either releasing hormones or copper ions to prevent pregnancy. Despite the negative associations with the Dalkon Shield, IUDs remain one of the most effective forms of contraception available and are widely used around the world today.