An intrauterine device (IUD) is a piece of T-shaped plastic, about the size of
a quarter, that is placed inside the uterus to prevent pregnancy. Two types of IUDs
are available: one is covered with copper, the other releases the hormone progestin.
How Does an IUD Work?
The copper-coated 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.
An IUD coated with progestin works in a similar way, but also thickens the cervical
mucus and thins the uterine lining. In some cases, it stops ovulation (the release
of an egg during the monthly cycle). This prevents sperm from fertilizing the egg
A progestin IUD also can be used to help reduce blood flow for girls who have heavy,
painful periods (dysmenorrhea).
How Well Does an IUD Work?
Both types of 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
The IUD is effective as soon as it is put in and it lasts a long time. A copper
IUD can work for 10 years. Progestin IUDs can work for 3 to 5 years, depending on
the brand. This makes the IUD a good option for women who are not ready to start a
family. Even though an IUD can stay in place for a long time, the doctor or nurse
practitioner can remove it at any time.
A doctor or nurse practitioner will check to be sure a woman doesn't have any STDs
before putting in an IUD. Getting an IUD put in while she has an STD could lead to
Abstinence (not having
sex) is the only method that always prevents pregnancy and STDs.
Are There Any Problems With an IUD?
The most common side effects of the IUD include:
irregular bleeding for the first few months
with the copper IUD, heavier periods with more cramps
lighter and shorter periods (or no periods) with some kinds of progestin IUDs
PMS-like symptoms such as moodiness, headaches, acne, nausea, and breast tenderness
with the hormonal IUD
Rare problems include:
Expulsion. An IUD can come out of the uterus by accident (called
"expulsion"). Sometimes a woman doesn't know this has happened. If an IUD comes even
part of the way out, it does not protect against pregnancy. A woman can check that
an IUD is still in place by feeling for the string (a doctor or nurse practitioner
can explain how to do this). After someone has an IUD inserted, she'll need to go
back for a follow-up visit to check that the IUD is properly in place.
Perforation of the uterus. There's an extremely small risk that
an IUD might push through the wall of the uterus while it is being put in.
Pelvic inflammatory disease (PID). There's a very low risk of
infection from bacteria getting into the uterus during IUD insertion. Most such infections
happen in the first 20 days after placement of the IUD.
Who Is an IUD Right for?
IUDs are a good birth control option for many girls and women. However, IUDs aren't
recommended for someone:
with PID or an active STD infection
who is already pregnant or may be pregnant
who has problems with her uterus, like a disease or malformation, or has abnormal
Experts recommend IUDs as a good birth control option for younger women and teens
because they last for many years, need no daily care, and are very effective at preventing
Where Are IUDs Available?
An IUD must be inserted by a doctor or nurse practitioner. This can be done at
the doctor's office, or at a health clinic, like Planned Parenthood. It can be inserted
anytime during a menstrual cycle as long as she is not pregnant.
How Is an IUD Put In?
The doctor or nurse practitioner puts the IUD in through the vagina, past the cervix,
and into the uterus. This only takes a few minutes from start to finish. People usually
feel some cramping during the placement, but it gets better within a few minutes.
Taking it easy for the rest of the day, using a heating pad, and taking over-the-counter
pain medicine can help with any discomfort after the IUD is placed.
How Much Does It Cost?
An IUD can cost anywhere from $0 to $1,300. The cost can vary depending on the
health insurance plan and the type of IUD. Many health insurance plans cover the costs,
and family planning clinics (such as Planned Parenthood) may charge less.
Because an IUD lasts for many years, the cost works out to about the same as monthly
birth control methods, such as the
Pill or ring.
When Should I Call the Doctor?
Someone with an IUD should call the doctor if she:
might be pregnant
notices a chance in the length of the IUD string
has a change in the smell or color of vaginal discharge