Ectopic pregnancies have risen dramatically in North America and in parts of Europe in the last 20 years. It has been suggested that the IUD may be 1 of the causes of the increase. This article examines data from studies in the United States, the United Kingdom, and Sweden and concludes that the risk of ectopic pregnancy for IUD users is not greater than, and possibly less than, that for nonusers of contraception. There are no data that support a causative relationship between nonmedicated or copper bearing IUDs and extrauterine pregnancy. Tables also summarize data from use effectiveness studies in the United States, Western Europe and Canada.