[An experimental epidemiologic study of 4 different IUDs].

In dafeng county of Jiangsu province, 710 healthy women, aged 22-32 years, were randomly allocated to use one of the title IUDs 3-9 months postpartum in a single-blind manner. UCD is an inert stainless steel device assuming the shape of the uterine cavity, i.e., isosceles triangular-shaped. The study was designed to be completed in 2 years, and presently, 2 year data were presented. Results show that there were significant differences in the crude and cumulative termination rates of the 4 groups as analyzed by the logrank test. Besides, the crude termination rater of SSR was significantly higher than those of the other 3 IUDs (P less than 0.01). The main reasons for discontinuation of SSR were pregnancy and expulsion. In regard to the removal due to bleeding and pain, MLCu250 seemed to be the best, followed by UCD, and TCu 220C was the worst.