Hormone releasing intra-uterine device (IUD)

Despite its effectiveness this contraceptive is not popular in Australia, perhaps due to myths and misconceptions around IUDs. Kirsten Braun

hormone releasing intra-uterine device

The hormone-releasing IUD belongs to a group of contraceptives referred to as long-acting reversible contraception (LARC). It consists of a T-shaped plastic device, about the size of a matchstick, which is fitted inside the uterus and slowly releases the hormone levonorgestrel, a form of progestogen. It provides contraception for up to five years and is considered 99.8% effective. In Australia the only hormone-releasing IUD currently available is Mirena.

LARCs are among the most effective forms of contraception as their effectiveness does not depend on correct or consistent use in the same way as taking the Pill or using a condom does. For example, LARCs have been shown to be 20 times more effective than the Pill in preventing an unintended pregnancy. Despite their effectiveness, LARCs are not widely used by women in Australia. These are answers to women’s common questions about the contraceptive.

Question 1: Is the hormone-releasing IUD painful to insert?

Women can find the procedure to insert the IUD painful. Women who have never been pregnant tend to experience more pain than those women who have had a baby. One small study found that on average women who had never been pregnant experienced a pain score of 6.6 (on a scale of 1-10) compared to 5.9 for women who had given birth. However, the study also found that despite the pain, women reported a willingness to have the IUD inserted again. A practitioner’s experience in inserting the device can have an impact on the level of pain, so women should go to a practitioner who is well experienced in the procedure. Some women also experience dizziness, fainting, nausea and low blood pressure on insertion. Following insertion, women commonly report cramp like symptoms, similar to period pain.

It was thought that taking a non steroidal anti-inflammatory medication (i.e., Ibruprofen)   before having the insertion could help reduce the pain but subsequent studies have not found any benefit for insertion pain, although these medications may help with the cramping pain afterwards.

Question 2: Does the hormone-releasing IUD cause irregular periods or spotting?

In the first few months after insertion many women experience spotting. While usually small in quantity, the frequency of the spotting can be very inconvenient to women. While the spotting does usually settle it can take between three to six months. Following this women will usually only experience a very light menstrual period. Within 12 months many women will not experience a period at all. While for many women this is welcomed, it can be disconcerting for others who are reassured they are not pregnant by their regular period.

Question 3: Will my partner be able to feel the strings?

The strings of the hormone-releasing IUD are designed to protrude through the cervix for easier removal by a practitioner and so a woman can check the strings to make sure the device is still in place. The strings of the IUD are nylon and are similar to a fine fishing line. If the practitioner fitting the device cuts the strings too short and/or on an angle, they can be felt by a partner during sex. If kept the correct length they will curl up around the cervix where they are less likely to be felt. An experienced practitioner will know how to cut the strings correctly. In one study that included 154 women with the hormone-releasing IUD, 85.6% of male partners had not noticed the strings.

Question 4: Does the hormone-releasing IUD cause pelvic infections?

Many women’s knowledge about IUDs and pelvic infections is based on the Dalkon Shield IUD, used in the early 1970s. The Dalkon Shield’s string assisted bacteria to move from the vagina into the uterus causing pelvic infections. The hormone-releasing IUD, however, has a different kind of string, and women with this IUD have no greater risk of pelvic infection than a woman without the IUD. There is an increased risk of pelvic infection during the first 20 days following insertion if a woman has an existing sexually transmitted infection (STI) like gonorrhoea or chlamydia and it is not subsequently treated. Therefore, women who are getting the hormone-releasing IUD inserted are usually screened for STIs. 

Question 5: Can the hormone-releasing IUD fall out?

Sometimes the IUD can be pushed out of the uterus either partially or completely. This is referred to as expulsion and it occurs in approximately five out of every 100 women. It is most likely to happen in the first few months following insertion. Women generally experience pain and or bleeding with expulsion but some women have no symptoms and are unaware it has occurred. If the IUD is expelled completely there is no contraceptive protection, but even if it is partially expelled this can reduce the effectiveness.

Last updated: June 2016

© Women's Health Queensland Wide Inc. This article was written by Kirsten Braun and reviewed by the Women's Health Queensland Wide editorial committee. It was first published in Health Journey 2016 Issue 2.

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