Four years experience with the Cu7 200 device-endouterine copper in fertility control

Abstract

Four years of experience with the Cu7 200 device have been completed. The 516 initial women studied accumulated a total of 17,554 months of observation. The most relevant events were: the net annual pregnancy rates, in four successive years of observation, were 2.3, 1.8, 2.1 and 0.9; rates for expulsions were 4.7 0.8, 0.0, and 0.4; and rates for bleeding/pain were 1.6, 2.1, 1.1, and 0.9, respectively, for each year. The quantitative gravimetric analysis of the remaining copper on the device, after four years of use, indicated that the loss of the metal is less than 30% of the original material; therefore the contraceptive activity of the device will continue for some years more. The mechanism of action of endouterine copper is discussed. © 1976.