The intrauterine contraceptive device (IUD) is an easy, safe and effective method of birth control. The IUD birth control offers convenience and cost-effectiveness for women who are looking for a long-lasting, reversible contraceptive method. IUDs are easy to insert and remove and, for a woman who wants to get pregnant, there is quick return to fertility after removal.
History of IUDs in the United States
During the early 1970s in the US, the Dalkon® shield IUD, was associated with sexually transmitted infections (STIs), pelvic infections, and infertility. All IUDs were subsequently removed from the U.S. market because of the intense negative publicity, though they continued in popular use in Europe and Latin America.
Further review showed that the increased risk of infections was mostly in women with multiple sexual partners and other risk factors for STIs, and that the Dalkon® shield design contributed to the these risks. Because of this new data, new IUDs returned to the US market in 1988.
The most current data available for the years 2006-2010 showed that of 62% of U.S. women of reproductive age (15-44) used a method of contraception. Of these women, 5.6% used an IUD birth control, an increase from 0.8 % in 1995.
The 2006-2010 data also showed that the IUD birth control was the sixth most common form of contraception used by women of reproductive age. By comparison, the birth control pill (28%) and tubal ligation (27%) were the most common forms of birth control in use 2006-2010.
Available IUDs in the U.S.
There are two types of IUDs currently available in the U.S.:
- Two hormonal IUDs: Mirena® and Skyla® - Mirena® is also available in the UK
- A copper IUD: ParaGard® Copper T 380A
How IUDs Work
IUDs are T-shaped, flexible, plastic devices with a string attached to the end. They easily fit into the pear-shaped cavity of the uterus. An IUD works primarily by preventing the sperm from reaching the egg. Hormonal and copper IUDS do this by slightly different mechanisms.
Mirena® and Skyla® are embedded with a hormone called levonorgestrel which is similar to progesterone, the hormone produced by the ovary after ovulation. Levonorgestrel is also present in some birth control pills. The hormone is slowly released from the IUD over time.
A hormonal IUD:
- Thickens the mucus in the cervical canal, making it difficult for sperm to swim from the vagina into the cavity of the uterus; this is the primary way it prevents pregnancy
- Damages or kills sperm
- Thins the lining of the uterus, which makes it difficult for any fertilized egg to implant in the uterus
- Interferes with the release of eggs from the ovaries (ovulation)
Mirena® is effective for 5 years. Skyla®, which releases a lower dose of levonorgestrel, is effective for 3 years
The Copper IUD
ParaGard® Copper T 380A IUD has copper wrapped around the stem and lasts for 10 years. It works by the following mechanisms:
- The uterus and tubes produce a toxic fluid that kills or damages sperm.
- Interferes with sperm movement
- Acts as a foreign body that interferes with the lining of the uterus, and therefore interferes with implantation of any egg that gets fertilized
Efficacy and Failure Rates
Because it does not rely on the woman's consistent and correct usage, compared to some of the other methods of contraception, the IUD birth control is one of the most effective methods available.
The hormonal IUDs have a failure rate of 0.2 %, and the copper IUD, 0.8%. That means that less than 1/100 women per year could get pregnant with an IUD in place. Compare this to a failure rate of 9% with the birth control pill, which is the most commonly used birth control methods in the U.S.
- IUDs are very effective, convenient, effortless, safe and easy to reverse.
- Users avoid having to take a birth control pill every day or have concern about a missed pill. Usage also avoids the inconvenience of frequent appointments for DepoProvera shots and contraceptive implants.
- Less costly than other methods of birth control because of its long-term use
- Easy to insert and remove
- Maintenance free because of its long-term usage
- If you want to get pregnant, your fertility returns to normal within a few weeks after the device is removed.
In addition, hormonal IUDs:
- Make periods lighter because of the thinner uterine lining; sometimes there are no periods at all
- May reduce the risk for cancer of the lining of the uterus because of the thinner lining
- Can be used for women with explained irregular or heavy vaginal bleeding because it stabilizes and thins the uterine lining
- Reduces menstrual cramps
- It reduces the risk of ectopic pregnancies compared to women not using birth control. If you get pregnant with an IUD in place, however, you have a higher risk of that pregnancy being ectopic.
- Can be used to treat endometriosis
The copper IUD can be used for emergency contraception if inserted within five days after unprotected sex.
Note that IUDs do not prevent STIs. If you have multiple sexually partners or your partners have other partners, you should use condoms as a precaution against STIs.
Complications and Side Effects From IUDs
IUDs are safe and side effects and complications are uncommon. Most of the complications occur at insertion.
- Perforations through the wall of the uterus occur in 1/1000 women, usually during insertion of an IUD.
- An IUD can become embedded in the muscle wall of the uterus after insertion in 1/1000 women. The IUD can usually be removed in a doctor's office using a special IUD instrument.
- Expulsion of an IUD occurs in 2 to 10/100 women. This more likely in the first three months after insertion. Expulsion is also more likely in women who have had no children or if the IUD is placed right after delivering a baby.
- An IUD string can be lost after insertion. Often it is just coiled up at the top of the vagina or inside the canal of the cervix and makes it difficult to reach with your finger. A doctor can look to see if this is this case. Sometimes the string disappears into the cavity of the uterus and your doctor may suggest removing it and placing a new one so you can check for the string.
In a case of suspected perforation, embedding, expulsion or lost string, an ultrasound of the uterus and pelvic area can locate the IUD.
- Irregular uterine bleeding, more commonly with the hormonal IUDs which stabilizes after 3-6 menstrual cycles
- Light periods with hormonal IUDs, which is a benefit for some women
- No periods in some women with hormonal IUDs, which might cause anxiety every month about a possible pregnancy
- Hormonal IUDs cause an increased risk of ovarian cysts because of the prevention of ovulation
- Heavy periods with copper IUD, which lightens within 3-6 cycles
- Uterine cramps after insertion are usually mild and diminish after 3-6 menstrual cycles.
Rarely, the hormonal IUDs can cause hormonal symptoms similar to birth control pills, such as headaches and acne, but these usually go away within 1-3 menstrual cycles.
There are contraindications to the use of IUDs as a method of birth control. Your doctor will take a detailed history from you to be sure that you don't have any of the following conditions:
- Undiagnosed irregular uterine bleeding
- Current pelvic infection
- Multiple partners without use of condoms because of risk for STIs
- History of ectopic pregnancies
- Abnormalities of the uterine cavity such as fibroids, or thickened band
- Abnormally shaped uterus
- Cervical, uterine or breast cancer
The IUD is not highly recommended for women who have never been pregnant because of risk of expulsion. If you have never been pregnant you can still use the IUD as long as you are aware of and accept this risk.
Previously, the IUD birth control was not recommended for adolescents. In 2012 the American College of Obstetricians and Gynecologists (ACOG) issued a committee opinion recommending the IUD for sexually active adolescents because of its high level of effectiveness.
Though an IUD can be inserted at any time, it is best inserted during the first five days of your menstrual cycle. This ensures that you are not close to ovulation and therefore decreases the chance of pregnancy at insertion.
In the hands of a gynecologist or other trained medical personnel, IUD insertion is easy and takes no more than 10 minutes to do. There is not much more involved in the procedure than a routine pelvic exam or Pap smear.
After inserting a speculum in the vagina, the doctor:
- Sterilizes the vagina and cervix with a solution
- Holds the cervix with a special instrument
- Checks the length of the cavity of your uterus with a measuring instrument
- Inserts IUD under sterile conditions
- Cuts the IUD string to about 1 inch (2.5 cm)
- Teaches you to feel your cervix and the IUD string with the tip of index finger
You check for the string every month right after your period finishes to ensure that the IUD is still in place.
Mild to moderate cramping is not unusual, but usually goes away quickly. Some doctors will ask you to take a non-prescription pain reliever an hour before insertion to decrease cramping.
As with insertion, IUD removal is quick and easy.
After speculum insertion, the doctor:
- Sterilizes the vagina and cervix with a solution
- Holds the cervix with a special instrument
- Holds the IUD string with grasping instrument quickly, but gently pulls it and in seconds the IUD is removed
There may be some vaginal bleeding and cramping after removal, which usually resolves quickly.
When to Call Your Doctor
After insertion or removal of an IUD, mild cramping and light vaginal bleeding can occur. Cramping usually do not last more than a few days. Call your doctor if you experience:
- Heavy vaginal bleeding
- Pain in your abdomen or pelvic area
- Increased vaginal discharge, especially if it has a bad odor
You should also consult with your physician if you cannot feel the IUD string after insertion or if you believe you might be pregnant.
The initial cost of an IUD can be $1000-$1600, but over its long-term use it is less expensive than the birth control pill or a birth control implant. However, as part of the covered preventive services in the Affordable Care Act (ACA), as of 2014 health insurance companies in the U.S. are mandated to pay for the cost of an IUD and its insertion and removal.
There are some exceptions to this mandate. Check with your insurance company for the specific details of your coverage before you see your doctor for IUD placement.
A Viable and Safe Option
IUDs are making a comeback as a viable birth control option for women in the U.S. since their return to the US market. IUD birth control has proven to be a safe, effective, long-term, easily reversible choice for women looking for a low-maintenance contraceptive option. Talk to your doctor about all the available birth control options to choose one that fits your individual situation.