IUCDs and Mirena IUSs
Intra-uterine device location
Ultrasound examination is the best way to locate an intra-uterine contraceptive device or a Mirena. If you are able to feel the string, then it is probably in the right position but the only way to be absolutely sure is by ultrasound examination.
When would I need an ultrasound examination?
- Your doctor may request an ultrasound examination to check the location of the IUCD or Mirena after the procedure
- You cannot feel the string
- It was a difficult insertion
- There were multiple fibroids which could interfere with the insertion
- There is any suspicion of pregnancy
- You are not experiencing the expected effect from the IUCD
- What type of examination?
We usually use the trans-vaginal approach because we get much better views, but occasionally the IUCD is a long way from the vagina and uterus, and so we need the trans-abdominal approach to give us a more global view of the pelvis.
Three-dimensional ultrasound is complementary to two-dimensional ultrasound. We use both.
This diagram of a Mirena IUS shows all the different ways that it works
A Mirena IUS correctly positioned in the uterus on 3d ultrasound
This Mirena IUS is rotated in the top of the uterus causing pain and bleeding. The string is seen going down the side of the cavity. It was easily removed.
How is a Mirena IUS or copper IUD usually removed?
When the time comes to remove a Mirena or IUD it is usually done by inserting a speculum into the vagina. The doctor then grasps the strings of the Mirena system or IUD as they come through the cervix and then with gentle traction the device is easily retrieved.
What if the strings are not seen?
It may be that the strings have migrated into the uterine cavity, the device has moved, or the strings have been cut too short to be seen in the vagina. In the office setting, various instruments have been used to help remove a Mirena system, but these devices are used blindly and may not be successful. In the past, many women have needed to have a general anaesthetic to remove the system.
How is ultrasound helpful?
Firstly, 3d ultrasound can check that the Mirena system is in the uterus. If it is then it will continue to work effectively. In this case many women will leave the Mirena in place until they are ready for it to be removed or replaced.
Mirena IUS are effective for 5 years.
If the Mirena is to be removed, then ultrasound can be used to see where the strings are. We can then use it to guide instruments to the strings or even to the Mirena system itself.
We are successful in removing 75% of Mirena systems in cases where the Mirena system could not be removed in the doctor's rooms. This has saved many women undergoing a general anaesthetic. We published a paper on this in the Australian & New Zealand Journal of Obstetrics and Gynaecology in 2013.
If another device is then placed into the uterine cavity we can check that it is in the right position, so you can go home knowing that it has been perfectly placed.
What happens on the day of the procedure?
It is not necessary for your bladder to be full. In fact we will get you to empty your bladder prior to performing an internal ultrasound scan of the uterus and ovaries. When the scan has been completed a speculum is inserted into the vagina just like when a Pap smear is performed.
With ultrasound guidance an instrument is guided into the uterine cavity to grasp the strings of the Mirena or IUCD. Then it is removed with gentle traction. If this is not successful we can use different instruments to grasp the Mirena or IUCD itself.
Most women experience minor discomfort however, some women may feel hot and dizzy for a short period of time. We encourage you to rest for 10 minutes or so before leaving our rooms.