The intrauterine device and ectopic pregnancy.

Abstract

The increasing incidence of ectopic pregnancies in Great Britain can be partly attributed to increasing use of IUDs, specifically, type of IUDs used. 1st-generation devices (e.g., Lippes Loop, Dalkon Shield, Saf-T-Coil) have an ectopic pregnancy rate of 5%, while 2nd generation (Copper-7 and Copper-T) devices have about 2% ectopic pregnancy rate. 3rd-generation devices have a higher proportion of ectopic pregnancies compared with 2nd generation devices. A calculation of number of ectopic pregnancies per million users of IUDs per year (derived from data on pregnancy rates and proportion of ectopic pregnancies from the pregnancy rates) shows that 1st generation devices have 4 times the risk of causing ectopic pregnancies among users (or 1-year pregnancy rate of 1.8-5.6 per 100 women) compared with 2nd generation devices. Thus, 1st generation devices should be eliminated from the market to reduce risk of ectopic pregnancy.