Use of IUDs is limited in developed countries because of perceived threats to future fertility, especially among nulliparas. These fears, shared by most practitioners, led to termination of most IUD sales in the US after July 1986. This review summarizes recent epidemiologic studies that confirm the increased risk of salpingitis and infertility in IUD users. The incidence of salpingitis has increased significantly and continuously over the past 20 years as a result of the development of sexually transmitted diseases. These infections may pass through the cervix and ascend to the tubes, where their sequelae include alteration of tubal function. The IUD is a risk factor for tubal infection because it favors ascending propagation of cervical infections. Studies in the US and Sweden indicate that IUD users have a 3 to 9 times higher risk of salpingitis than do nonusers. Studies in Lund, Sweden, and Seattle, USA, have demonstrated a significantly higher risk of salpingitis and infertility among nulliparas. Studies indicating increased risk of salpingitis among nulliparas are often criticized on methodological grounds for poor control of age factors, but it is known that young women (who are often nulliparas) are more exposed to the risk of salpingitis. The 1st studies suggesting a link between salpingitis and IUDs were criticized on 2 grounds: 1) that the risk of salpingitis varies according to the type of IUD and 2) that the risk of salpingitis in IUD users should be measured in terms of women not using any contraception, since hormonal methods are now known to protect against salpingitis. But studies have shown an increased risk of salpingitis even in Sweden, where the Dalkon Shield, associated with particularly high rates of salpingitis, was never marketed. Estimates of the relative risk of salpingitis among IUD users compared to women not using any contraception have already been made and range from 1.5 to 3. The evidence indicated that IUDs are a risk factor for salpingitis and consequently a threat to future fertility. An even higher risk among nulliparas appears reasonable but is controversial on methodological grounds. IUD use may sometimes be appropriate for older married women with stable sex lives for whom the vascular risks of hormonal methods are increasing. IUD use is contraindicated among young nulliparas because of the possibility of infertility.