2 year comparative clinical experience with 3 IUDs in China.

A previous report of a 1 year comparative study of larger numbers of the TCu380Ag TCu220C and Mahua Ring IUDs showed that the TCu220C appeared to have significantly lower rates of pregnancy and expulsion fewer removals for bleeding and pain and thus a higher continuation rate. In a continuation of this study from December 1 1980 to February 28 1982 2762 parous women were randomly fitted with 1 of these 3 IUDs in 5 hospitals in Tianjin. From the literature and this study the TCu380Ag consistently appears to be the most effective IUD; the TCu220C shows superior efficacy in preventing pregnancy and tends to become almost as effective as the TCu380Ag. The main reason for the lower pregnancy rates of these 2 IUDs is undoubtedly the presence of copper collars on the horizontal arms which release more copper ions close to the fundus where implantation normally occurs. This study shows that the medicated Copper-T devices are more effective in preventing pregnancy than is the non medicated stainless steel Mahua ring. In the 2 year study the TCu380Ag had a significantly higher expulsion rate than the TCu220C possibly due to improper insertion of the former at one of the 5 hospitals participating in the study. There were no statistically significant differences in removal rates among the 3 IUDs. No definite pelvic infection or ectopic pregnancy was observed which perhaps might be accountable by strict selection of users aseptic technique and low incidence of sexually transmitted disease.