What is an IUD? How does an IUD work to prevent pregnancy? What are the benefits and potential side effects of IUDs? Get answers to these and other questions about female birth control IUDs.

Understanding the IUD: Definition and Types

An intrauterine device (IUD) is a small, T-shaped plastic device that is placed inside a woman’s uterus to prevent pregnancy. There are two main types of IUDs available: the copper IUD and the hormonal (progestin) IUD.

How IUDs Work to Prevent Pregnancy

The copper IUD prevents pregnancy by not allowing the sperm to fertilize the egg. It may also make it harder for a fertilized egg to implant in the uterus. The hormonal IUD works in a similar way, but also thickens the cervical mucus and thins the uterine lining. In some cases, it can stop ovulation, the release of an egg during the monthly cycle, further preventing fertilization.

Effectiveness of IUDs in Preventing Pregnancy

Both types of IUDs are highly effective at preventing pregnancy. Over the course of a year, fewer than 1 out of 100 typical couples using an IUD will have an accidental pregnancy. The copper IUD is effective as soon as it is inserted and can last up to 10 years, while the hormonal IUD can work for 3 to 6 years, depending on the brand.

Potential Side Effects and Risks of IUDs

The most common side effects of IUDs include irregular bleeding, heavier periods with more cramps (with the copper IUD), lighter and shorter periods (or no periods) with some progestin IUDs, and PMS-like symptoms such as moodiness, headaches, acne, nausea, and breast tenderness (with the hormonal IUD). Rare but serious problems include expulsion of the IUD, perforation of the uterus, and pelvic inflammatory disease (PID).

Who is an IUD Right For?

IUDs are a good birth control option for many people, but are not recommended for someone with pelvic inflammatory disease (PID) or an active sexually transmitted infection (STI), who is already pregnant or may be pregnant, or who has problems with their uterus, such as a disease or malformation, or abnormal bleeding. Experts often recommend IUDs as a good birth control option for younger adults and teens.

Accessing and Inserting an IUD

An IUD must be inserted by a doctor or nurse practitioner, either at a doctor’s office or a health clinic like Planned Parenthood. The insertion process only takes a few minutes, but may cause some cramping. Over-the-counter pain medication and a heating pad can help with any discomfort after the IUD is placed.

Cost and Insurance Coverage for IUDs

The cost of an IUD can vary depending on your health insurance coverage and the type of IUD. Many health insurance plans cover the costs, and family planning clinics may charge less, particularly for teens and young adults. Because an IUD lasts for many years, the overall cost works out to about the same as monthly birth control methods.

When to Contact a Doctor

If you have an IUD, it’s important to call your doctor if you suspect you might be pregnant, notice a change in the length of the IUD string, have a change in the smell or color of your vaginal discharge, have lasting cramping or pain, have an unexplained fever or chills, or experience belly, pelvic, or pain during sex.

What is the difference between the copper IUD and the hormonal IUD?

The main difference is that the copper IUD prevents pregnancy by not allowing the sperm to fertilize the egg and potentially making it harder for a fertilized egg to implant, while the hormonal IUD also thickens the cervical mucus, thins the uterine lining, and in some cases, stops ovulation. The copper IUD is effective immediately and can last up to 10 years, while the hormonal IUD lasts for 3 to 6 years depending on the brand.

How effective are IUDs at preventing pregnancy?

IUDs are very effective at preventing pregnancy. Over the course of a year, fewer than 1 out of 100 typical couples using an IUD will have an accidental pregnancy. This makes IUDs one of the most effective forms of birth control available.

What are the potential side effects of IUDs?

The most common side effects of IUDs include irregular bleeding, heavier periods with more cramps (with the copper IUD), lighter and shorter periods (or no periods) with some progestin IUDs, and PMS-like symptoms such as moodiness, headaches, acne, nausea, and breast tenderness (with the hormonal IUD). Rare but serious problems include expulsion of the IUD, perforation of the uterus, and pelvic inflammatory disease (PID).

Who should not use an IUD?

IUDs are generally not recommended for someone with pelvic inflammatory disease (PID) or an active sexually transmitted infection (STI), who is already pregnant or may be pregnant, or who has problems with their uterus, such as a disease or malformation, or abnormal bleeding.

How much do IUDs cost, and are they covered by insurance?

The cost of an IUD can vary, but many health insurance plans cover the costs. Family planning clinics may also charge less, particularly for teens and young adults. Because an IUD lasts for many years, the overall cost works out to about the same as monthly birth control methods.

When should I call the doctor about my IUD?

You should call your doctor if you suspect you might be pregnant, notice a change in the length of the IUD string, have a change in the smell or color of your vaginal discharge, have lasting cramping or pain, have an unexplained fever or chills, or experience belly, pelvic, or pain during sex.