Intra-uterine device, spring coil, plastic, 1of 2, 1970-1981
Its distinctive shape gives this plastic intrauterine device (IUD) its more common name of the coil. It is shown on the right with other IUDs. An IUD is a contraceptive worn inside the uterus. It works after conception. An IUD stops a newly fertilised embryo implanting and growing in the lining of the uterus. IUDs became popular in the 1960s and 1970s. However, scares and litigation in the 1980s made them less common. More successful varieties were introduced in the 1990s. The IUD is now the most inexpensive long-term reversible method of contraception available.