Levonorgestrel intrauterine device with absence of threads: don't take expulsion for granted! A case series of possible errors in ultrasound evaluation, in case of "lost IUDs".

Levonorgestel intrauterine devices are safe contraceptive methods, with even medical indications. However, they may present rare, but severe complications such as perforation and abdominal dislocation. Ultrasound assessment may be limited if a medicate intrauterine device is lost, due to its particular echogenicity. We report cases complicated by loss of intrauterine devices. Based on this experience we believe that ultrasound should always be associated to an X-ray examination to prevent misdiagnosis, especially in case of loss of a levonorgestrel device. Although our conclusions are not innovative and the cases are limited, we believe they can be a reminder in clinical practice to avoid not so infrequent complications and clinical errors. We would also like to recall the limitations of ultrasound in locating levonorgestrel intra uterine devices and stress that one should never take for granted the expulsion of the device in case of lost its threads.