The intrauterine device and ectopic pregnancy.

Based on data given by case-control and cohort studies the relationships between current and past IUD use, duration of IUD use and the type of IUD were evaluated to determine the risk of ectopic pregnancy among IUD users. The results of this review indicate that current and past IUD users do not have an increased risk of ectopic pregnancy. No relationship was found between the duration of IUD use, for either current or past IUD users, and the risk of ectopic pregnancy. Pooled data from clinical studies of different types of IUD showed that the lowest risk of ectopic pregnancy was for users of copper-bearing IUDs, and the highest risk was for users of progesterone-releasing IUDs. Further research is needed to evaluate the ectopic pregnancy risks to past IUD users, especially in view of recent studies which have shown that these women may be at a higher risk of infertility.