Missing IUD Strings

Missing strings means the threads cannot be seen at the external os at routine follow up or when removal is planned. The device may be in the uterus with retracted threads, expelled unnoticed, or perforated into the pelvis. Pregnancy must be excluded first, because the strings may be lost into the uterus during pregnancy as it enlarges.

Common causes. Threads cut too short, retraction into the cervical canal or uterus, partial or complete expulsion, perforation, previous removal not remembered, and pregnancy.

History. Date and type of insertion, whether the patient saw the device or threads, pain, bleeding, last menses, recent unprotected sex, and symptoms of pregnancy.

Examination. Speculum examination looking for threads or a device in the canal, and bimanual examination.

Pregnancy exclusion. Reasonably certain if no intercourse since the last menses, consistent use of a reliable backup method, within 7 days of the start of menses, or within 4 weeks postpartum. Otherwise do a pregnancy test.

Differential diagnosis. Retracted threads with device in situ, expulsion, perforation, pregnancy, previously removed device.

Investigations.

• Ultrasound to locate the device.
• If not seen in the uterus, a plain abdominal and pelvic film to locate a perforated or expelled device.
• Hysteroscopy or laparoscopy if imaging suggests perforation or extrauterine position.

Backup. Advise condoms or another method until the device is located.

Stepwise approach.

1. Exclude pregnancy.
2. Examine the cervix with a speculum and look for threads in the canal.
3. If threads are not seen, gently feel the canal with a thin probe or use a cytobrush to draw threads down, taking care not to push the device.
4. If still not found, do an ultrasound.
5. If the device is in the uterus, either leave it and reassure the patient, or remove it with an alligator or crocodile forceps or hysteroscopically if removal is wanted.
6. If the device is not seen on ultrasound, do a film to look for an extrauterine device.
7. If the device is not found on either test, it was probably expelled, and a new device can be placed once pregnancy is excluded.

Pregnant with missing strings. Ultrasound to locate the device. If in the uterus, she may continue the pregnancy and seek care for heavy bleeding, cramping, pain, abnormal discharge or fever. If it is not located, expulsion may have occurred.

Extrauterine device. Refer for removal by laparoscopy or laparotomy.

Emergency contraception. If unprotected sex has occurred and the device cannot be confirmed in the uterus, give levonorgestrel 1.5 mg orally as a single dose within 120 hours, or ulipristal acetate 30 mg orally as a single dose within 120 hours, while the device is located.

Analgesia and antibiotics. None routinely, except where infection is suspected.

Follow up. Confirm location of the device before closing the visit. Use condoms or another method until the device is confirmed in the uterus or replaced.

Method decisions. If the device is confirmed in the uterus and the patient wants it, continue it and teach her when to return. If expelled, replace or choose another method. If perforated, remove and choose another method.

Referral and escalation. Refer extrauterine devices, suspected perforation, embedded devices that cannot be removed in the clinic, and pregnancy with a displaced device.