Intrauterine devices (IUDs) are small devices placed in the uterus to interrupt the process of insemination. They are one of the most effective forms of birth control. Among women using IUDs, two to eight in every thousand get pregnant in a year of typical use. They are very popular around the world.
IUDs have been on and off the market for decades. Currently, there are three brands of IUDs available in the United States: ParaGard is a copper IUD, and Mirena and Skyla are hormonal IUDs that use progestin.
IUDs are an excellent choice of birth control for many women. However, they may not be the best choice for women who are at a high risk for sexually transmitted infections (STIs).
Both types of IUD work by making it difficult for the sperm to reach the egg.
ParaGard causes inflammation response in the lining of the uterus. This inflammation is toxic to sperm. It also makes the uterus hostile to implantation, if fertilization occurs, though recent studies have failed to find evidence that fertilization ever occurs. ParaGard works for up to 10 years after it is inserted.
Mirena works to thin the lining of the uterus, to prevent the transport of sperm into the fallopian tubes where fertilization must occur.The progestin it releases also thickens cervical mucus and can prevent ovulation. Mirena can last for up to five years after insertion. Skyla is smaller and contains a lower dose of progestin, thins the uterus lining, and can last up to three years.
An IUD is inserted by a healthcare professional. Make an appointment with your doctor to determine if the IUD is the best birth control option for you.
Your doctor will insert the IUD through the cervix and into the uterus. The procedure usually takes less than 15 minutes. It can be done with or without local anesthesia. You will probably feel some cramping or discomfort.
The IUD can be inserted any time it is certain that you are not pregnant.
There is a very small risk of expulsion when the IUD is implanted. Therefore, for the first few months, it is important to check that it is still in place. You should do this every month.
To check your IUD:
1. Wash your hands with soap and water.
2. Put your finger into your vagina until you touch your cervix.
3. Feel for the string ends.
You should be able to feel the string. If the string feels shorter or longer than normal, there may be a problem. You should not feel the hard end of the IUD against the cervix.
If there is a problem, do not pull on the string or try to reinsert the IUD yourself. Instead, make an appointment with your doctor. While you are waiting for the IUD to be reinserted, use an alternative form of contraception.
Expulsion is rare. If it happens, it will probably be during your period. Expulsion is most likely in the first few months after insertion.
Both types of IUDs are more than 99 percent effective at preventing pregnancy. They are one of the most effective types of birth control available. They are also one of the most convenient forms of birth control because they work for between three and 10 years.
An IUD has many benefits. It is:
- convenient—does not require preparation before sex
- usable during breastfeeding
quickly reversible if you want to get pregnant
- inexpensive—after the initial cost of insertion (ranging from $500 to $1000), there are no more costs for five to 10 years
Mirena can also help relieve:
- menstrual pain
- heavy periods
- pain from endometriosis
ParaGard can also be used as a form of emergency contraception. According to Planned Parenthood, it is 99.9 percent effective at preventing a pregnancy if inserted within five days of unprotected intercourse.
- IUDs have the following disadvantages:
- they do not protect against STIs
- insertion can be painful
- ParaGard may make your periods heavier
- ParaGard may also make your menstrual cramps worse
- Mirena and Skyla may make your periods irregular
These side effects usually go away within the first six months of use.
There is a small risk of infection when you use an IUD. This risk is highest during insertion. You should not get an IUD if you have, or may have, an STI. In addition, IUDs are not recommended for women who:
- might be pregnant
- have untreated cervical cancer
- have uterine cancer
- have unexplained vaginal bleeding
- are, or might be, allergic to copper (ParaGard only)
- have Wilson’s disease (ParaGard only)
- have severe liver disease (Mirena and Skyla only)
- have, or may have, breast cancer (Mirena and Skyla only)
Because there is a slight risk of infection when the doctor inserts the IUD, they may require that you get tested for STIs first.