Method to the Madness? Get to Know the Different Types of IUDs

In Pregnancy/Postpartum by Jandra Mueller1 Comment

By Jandra Mueller


In my last blog, One and Done: The IUD and the Future of Birth Control, I talked about how the American College of Obstetrics and Gynecology (ACOG) are recommending long acting reversible contraceptives (LARC) as their preferred contraceptive option. The two main forms discussed were the implant and the IUD. In part one I mentioned that although the implant is excellent in preventing pregnancy, it is not the BEST option of the two because of the rise in sex hormone binding globulin (SHBG). Both the implant and oral contraceptives can have undesirable side effects because of the the rise in SHBG.  To read more about this, read Dr. Goldstein’s blog post here.


That leaves the IUD as a reasonable choice of birth control. ln this post I’ll go more in depth about the different types of IUDs, and provide some education about what the research has to say about who can and would benefit from the use of an IUD.




Paragard is a copper IUD, which means it is 100% hormone-free. It works to prevent pregnancy for up to 10 years by acting like a natural spermicide; the presence of copper and copper ions in the uterus renders the sperm useless. This sounds great after all that hormone talk right? Unfortunately, this isn’t exactly the case. The copper IUD tends to worsen menses, especially in women who suffer from endometriosis or adenomyosis.7 It also has a higher discontinuation rate in women, it is suggested but not confirmed, that the size of it may be an issue.The paragard is a larger IUD, measuring 32mm by 36mm.


Did you know: In women who have not given birth, the average size of a uterus is 27mm wide and 27 mm long?  6


Hormone releasing IUDs (Mirena, Skyla, Liletta)


The hormone releasing IUDs are T-shaped flexible structures that are placed into the uterus and release varying amounts of levonorgestrel, a form of progesterone. The primary way this IUD works is that the progesterone released into the uterus prevents the endometrium (or inner lining of the uterus) to build up, which prevents implantation of the egg. In addition, it thickens the cervical mucus, making it harder for sperm to pass.


Similar to the implant, there is no synthetic estrogen, so our ovaries are free to continue producing our sex hormones. There are not the systemic effects we see with all the other forms of contraception, including the implant, which raises SHBG; so our testosterone stays available for our body to use. It is suggested systemic testosterone is important for libido and vulvar tissue health.


In addition to their effective contraceptive benefits, there are non-contraceptive benefits of the hormone releasing IUDs. The hormone-releasing IUDs may help women who suffer from painful or heavy periods, adenomyosis, as well as prevent or treat endometrial hyperplasia in women with polycystic ovarian syndrome and in estrogen users.8 The hormones released from the IUD protect the endometrium from stimulation in women who are taking estrogen replacement therapies (usually post-menopausal women) and in women who take tamoxifen (in women with receptor-positive breast cancer). 8


So why are there so many hormone releasing IUDs? What’s the difference?


Mirena, Skyla, and Liletta




The Mirena was the first hormone-releasing IUD to be FDA approved in the U.S. It was formerly approved for use up to five years, and just this month the FDA approved use for seven years. It used to be thought that it was used only for women who have had kids previously due to pain with insertion and the uterine size. Studies show however, that there was no difference in the rate of expulsion, contraceptive failure, and premature discontinuation in women who have or have not had babies. The only difference shown was that nulliparous women (women who have not had a baby) reported pain with IUD use compared to women who have not had a baby.7


The size of the Mirena is a bit smaller than Paragard, but comparable it measures 32mm wide by 32mm long. One study that looked at IUDs in nulliparous women showed the statistics were similar in women who have had babies.


      96% of women had successful insertion on their first attempt


      80% of women had minimal to no pain one week after device insertion


      There was a high satisfaction rate: 83% said they were ‘happy’ or ‘very happy’ with the device. 9


Best population: Studies show that any woman – young or old, baby or no baby – can safely and effectively use the Mirena IUD 11. Also, any women that suffer from endometriosis, adenomyosis, or painful or heavy periods may have significant benefit. 8




Skyla was introduced in 2013 as a hormone-releasing IUD FDA approved for 3 years as it has less total progesterone than the Mirena. It is essentially a “mini-Mirena.” It was primarily created because Mirena was too large for some nulliparous and even postmenopausal women. The Skyla measures 28mm wide and 30mm long.


Best population: Since the actual IUD is smaller in size than the Mirena, there is some evidence to suggest for nulliparous women it is a good option to help reduce pain with insertion. This is often why many nulliparous women are hesitant to choose an IUD as a contraception method. 11




Liletta is the newest addition of the IUDs. It became FDA approved in 2015 for use up to three years. This IUD is basically an exact replica of the Mirena; it is the same size and has the same amount of total hormone, though it is released at a different rate. The FDA will likely increase the usage of this device to five years once more research is performed. The benefit of this device is that it was meant to be a more affordable option than the others, as one of the barriers to using this form of contraception is the cost for some consumers.


Best population:  Same as the Mirena; however, this may also be a better option for women whose insurance plans do not cover the cost of the IUD. This IUD was made to be the most cost effective for women. 12


Which LARC should I choose?


Just like many of you, I too have suffered the effects of taking systemic hormones, and have been frustrated that many doctors never offered me this form of contraception. Also like many of you and many women I see on a daily basis, I was young when I was started on the pill for a reason other than preventing pregnancy, which resulted in a 7-year history use of OCP use, side-effects and all. But now there are other options, and you should utilize them.


If you are currently on the pill, the patch, the shot, or even have the implant, I encourage you to talk with your ObGyn about the options for an IUD. If your current insurance company does not cover the IUD or you do not have insurance, check out this website for information on how to get an IUD at low or no cost to you.


If you read this blog and you are suffering from painful intercourse, vulvodynia, or vestibulodynia, or identify with any of the other side-effects that were mentioned, talk to your ObGyn about your symptoms and consider finding a pelvic floor physical therapist to evaluate you and help identify the source of your pain. For more information on female pelvic pain, click here.


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  1. Thank you for sharing the different types of IUDs. I would suggest you add “pregna” to your list. It is also, one of the best contraceptive devices. I am using it for the last 2years and have no issues with it.

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