The "forgotten" intrauterine device: a cause of infertility.

We present a case of infertility due to a "forgotten" IUD. Users of intrauterine devices are reported to have an increased risk of frank or subclinical genital infections which later may be the cause of infertility. Other mechanisms of causing infertility are possible. During the last two years we have seen three infertile patients with an IUD in situ. Two had ovulation, and one got pregnant immediately after the IUD was removed.