Fortunately IUD pregnancy failures are rare, but here is what you need to know in this situation if you have an IUD and you have a pregnancy as shown in this ultrasound.
Not having menstrual periods is normal with the medicated IUDs like Mirena and Liletta.
Do not assume that the pregnancy test was false positive. The copper in the ParaGard and the levonorgesterel in the medicated IUDs cannot interfere with pregnancy tests.
If you do have an IUD for contraception, and you get a positive pregnancy test, you probably ask yourself, what next? Well, make your gyno appointment promptly, this is a condition that is not typically an emergency, but it can be and it’s not handled over the phone or on a blog, or through self diagnosis! Accurate pregnancy diagnosis, pelvic examination, and pelvic ultrasound are the cornerstones of the evaluations.
IUDs are better at preventing pregnancy in the uterus than they are at preventing the pregnancy from occurring in the fallopian tube. That being said, some researchers from University of Texas Southwestern Medical Center in Dallas decided to look back at over 4100 women who had IUDs and of those 42 cases who became pregnant in their institution, over about a year period of time, to help understand what these women could expect when they got to their gyno and what actually happened to their pregnancies. They had very specific ways they looked at their ultrasound to prove there was no pregnancy in the fallopian tube, or partially in the fallopian tube. IUDs are considered in place if both arms of the upper portion of the IUD are located in the mid to upper region of the uterus. Their group studied happened to have more ParaGard IUDs than the medicated ones. A very few of the patients were lost to follow up, a very few had miscarriages and only three were treated as tubal pregnancies. Bleeding was the most common symptom for these women. It was 3 times more likely to become pregnant if the IUD was poorly positioned in the uterus. In many cases when a woman is found to be pregnant with an IUD, the IUD has already been expelled, and in most if found, it can be easily removed. About ¾ of the women were able to carry to term, even women who have an IUD that cannot be removed, can most likely go on to term, as only about half of the IUDs were able to be removed during the ongoing pregnancy. This did however leave about ¼ women with an IUD that lost their pregnancy before 20 weeks. Women with their IUD out of position when they had the contraceptive failure and conceived, were just a bit more likely to have some pain, but it wasn’t actually statistically significant in this study. So to summarize, IUDs are still thought of as excellent contraception, and are right for many women, here's a tool to work through to help women still considering IUDs to think about it.
However, for women who do become pregnant with an IUD, you need to see your gyno, you should have your IUD removed if you are going to continue your pregnancy and your IUD most likely will be able to be removed. Most women with an IUD and a pregnancy will most likely be able to continue on to full term without complications from the IUD.