IUDs: The Benefits and Side Effects

By: Dana Leslie, CNP • Posted on August 21, 2023 • Updated September 27, 2024

What is an IUD?

Intrauterine contraception (IUD) is the most commonly used, long acting, reversible contraceptive worldwide. It is a popular choice among women because it is very effective, low cost, easy to use and safe. An IUD has the same effect as sterilization, but is a reversible, non-surgical birth control option.

IUDs are T-shaped and are made of plastic and release either progesterone or copper to enhance the contraceptive effect. IUDs offer multiple years of protection ranging from 3-10 years depending on which IUD is used.

Myths about IUDs

1. The most common myth about IUDs is that they cause infection, which stems from complications in the construction of the Dalkon Shield IUD from the 1970s that is not used today. IUDs currently are constructed much differently using monofilament tail strings.
2. Another frequent misconception is that IUDs increase the rate of ectopic pregnancy. Actually, the overall risk of ectopic pregnancy is very low with an IUD in place, although if pregnancy does occur, it is more likely to be ectopic.
3. IUDs are not associated with an increased risk of infertility. Patients should return to fertility shortly after the IUD is removed. If you are not ready to have a child when the IUD is taken out, you should use another form of birth control or condoms.

Benefits of the IUD

1. Highly effective contraception
2. Ease of use
3. Place it and forget it
4. Safe for most women, including teenagers and women who have never had a baby
5. Can be used with patients who are smokers and/or patients with high blood pressure
6. Can be used after having a child and as emergency contraception (Copper IUD only)
7. Long-acting, reversible method of contraception with very few side effects
8. Very cost effective when used over the life of the IUD

How does an IUD work?

The presence of the IUD in the uterus causes a foreign body effect as well as local changes in the lining of the uterus because of the medicine released (levonorgestrel or copper). This foreign body effect (thickening the cervical mucus) is toxic to sperm, changing the way they move so they are unable to get to an egg.

The hormonal IUDs also have a variable effect on suppressing ovulation (releasing a mature egg), but this is not thought to be the major mechanism in pregnancy prevention.

2 Types of IUDs

1. Non-Hormonal - Paragard® Copper IUD

The Paragard® Copper IUD is a T- shaped IUD with a plastic wire wound around the stem.

Benefits of the Copper IUD

• Approved for up to 10 years of use
• Highly effective with a pregnancy rate in the first year of use of 0.6%
• Lack of exposure to hormones and the continuation of menstrual cycles in women who prefer cyclic (monthly) bleeding
• Can be used for emergency contraception
• Least expensive

Side effects and cons of the Copper IUD

• Slightly, higher failure rate than the hormonal IUDs
• Does not protect against genital tract infection, while the hormonal IUD thickens the cervical mucus potentially preventing genital tract infections
• Menses may be heavier, longer and with more cramping in the first month after insertion of the copper IUD. However, many women report these symptoms return to normal after the first 6 months of use
• May worsen menstrual problems such as heavy periods, painful periods or endometriosis type pain

2. Hormonal IUD - Levonorgestrel

There are 4 variations of the hormonal IUD. Each variation has different doses of the Levonorgestrel hormone and their length of use varies from 3 to 7 years. The width of the IUD is also different in the insertion tube, which can influence ease of insertion. All hormonal IUDs are T-Shaped.

4 hormonal IUDs

1. Mirena® - contains 52 mg LNG and is 4.4 mm wide. It can be used up to 5 to years for bleeding and up to 8 years for contraception. You can get the Mirena exchanged earlier if needed, but not all insurance will approve that
2. Liletta® - contains 52 mg LNG, can be used for up to 8 years and is 3.8 mm in width
3. Kyleena® - contains 19.5 mg LNG, can be used for up to 5 years and is 3.8 mm in width
4. Skyla® - contains 13.5 mg LNG, can be used for up to 3 years and is 3.8 mm in width (Mirena®'s little sister)

The Mirena® IUD is FDA approved to treat heavy menstrual bleeding and may avert the need for a hysterectomy. Kyleena® and Skyla® are only approved for contraception, they are not FDA approved to treat heavy bleeding.

Benefits of the hormonal IUD

• The main benefit that is appealing to most women is the lighter, or even absent, menses. This is best for women with heavy menses or women who will not mind if their periods disappear or is markedly reduced
• Does not contain estrogen, making it safe for women who are unable to take estrogen (i.e. high blood pressure, smoking cigarettes after age 35, and those with history of deep vein thrombosis or any other condition where exogenous estrogen needs to be avoided)
• Decrease in heavy menstrual bleeding
• Decrease in menstrual cramping
• Decrease in pelvic inflammatory disease
• Decreased overgrowth of the lining of the uterus which, in some women, can be a uterine cancer precursor
• The effect of LNG (progestin) is primarily at the level of the lining of the uterus (endometrium), which means that there is not a high systemic absorption that occurs. Oral contraceptives, Depo Provera® and the Nexplanon® have a high systemic absorption

Side effects of the hormonal IUD

These progestin levels, which slowly decline over time, can cause side effects in some women. The most common side effect is changes in bleeding patterns which includes:

• Prolonger bleeding (59%)
• Unscheduled bleeding (up to 52%)
• Lack of any menstrual bleeding (6-40%). This varies depending on the type of IUD selected - higher levels of progesterone means increased occurrence

Good news is that bleeding symptoms typically improve within the first six months of having an IUD.

Is Insertion Painful?

A large concern for patients considering the IUD is what is the insertion process like and will it hurt.

Your women's health care clinician (physician, advanced practice nurse or physician assistant) will insert the IUD in the office typically, in an outpatient setting.

The feeling of discomfort that the patient feels is from the opening of the cervix. The intensity of the pain varies for each person. Many describe the pain as an intense menstrual cramp. The good news is, the pain only lasts a few minutes. Some providers will prescribe you a medication prior to the insertion of your IUD to help “soften” the cervix. Also it is often recommended to take Tylenol prior to your appointment and to eat a small meal.

How do I choose which IUD is for me?

Things to consider when choosing your IUD:

• Do I want to have a monthly period?
• Do I want my period to be lighter?
• Do I have a tolerance for irregular/unscheduled bleeding?
• Will I be ok with not having any menstrual bleeding?

IUDs are very safe, effective and long-acting reversible methods of contraception. There are few contraindications to use them and are an option for women of all ages!

Talk to your women's healthcare clinician about your preferences, goals and options to discover which IUD option might be the best for you.

Be Strong, Be Healthy, Be in Charge!

- Dana Leslie, CNP

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