The 'tail' of a missing intrauterine contraceptive device.

This case presents a cautionary tale demonstrating the importance of skilled ultrasonography for the correct location of an intrauterine device (IUD) lying within the uterine cavity where the threads are 'lost'. Accurate ultrasound examination can ensure the avoidance of unnecessary x-rays or surgery. The case also acts as a reminder that a missing thread of an IUD does not imply that the device is misplaced.