2 intrauterine devices, Copper-T-200 and a new type, Nova-T, were compared in a study conducted simultaneously in Denmark, Finland and Sweden over a period of 1 year. The results obtained were very similar with the exception of the pregnancy rate which is 3 times lower with Nova-T than with Copper-T-200. There was 1 case of uterine perforation with a Copper-T-200, 1 case of pregnancy with a Nova-T and 2 ectopic pregnancies with Tcu-200. Bleeding and pain were the main reasons for IUD termination, with a comparable rate. The rate of expulsion for both devices is almost 50% of the termination rate for bleeding or pain. No pelvic infection has necessitated surgery. The rate of termination for infection is substantially higher in women under 25 and appears to depend on the age of the subject rather than on parity. Nova-T is designed in such a fashion that it keeps its shape better than Copper-T-200. This helps avoid the shifting of the device and might explain the lower pregnancy rate. It is equipped with a flexible loop at the end of the vertical arm, designed to avoid perforations of the uterus, which is 1 of the disadvantages of Copper-T-200. However no perforation was recorded in the study with either device, and consequently the efficiency of this loop has yet to be proved. Nova-T's copper thread has a silver core which prevents fragmentation.