Myths About the Intrauterine Device (IUD)

Published: 8 October 2026 · Medically reviewed by: Op. Dr. Murat Alpay

What is an intrauterine device (IUD), how does it work and what are the most common myths about it? Insertion, side effects, who cannot use it and removal.

Everyone has an opinion about the IUD, but a good part of these opinions are wrong: "women who have never given birth cannot use it," "it causes infertility," "it is very painful to insert," "it causes cancer." This article explains what an intrauterine device (IUD, also called a "coil") is, how it works and the truth behind the most common myths. To compare other methods, you can also read our article on birth control methods.

What Is an IUD and How Does It Work?

An IUD is a small birth control device, usually T-shaped and made of flexible plastic, placed inside the uterus. There are two main types:

Copper IUD (contains no hormones): Its frame is wrapped in a thin copper wire. It causes a mild, local and harmless reaction inside the uterus; the copper released impairs the movement and survival of sperm, so sperm become ineffective before they can fertilize the egg.

Hormonal IUD: It holds a reservoir of levonorgestrel, a progesterone-like hormone, and releases a very small amount into the uterus every day. It works in two ways:

• It thickens the mucus at the cervix (the neck of the womb) and blocks sperm from passing into the uterus.
• It thins the lining of the uterus (endometrium) so that it is not suitable for a pregnancy.

Because the amount of hormone reaching the blood is very small, it mostly does not stop the ovaries from working or ovulation; in most users, ovulation continues.

How Effective Is It?

IUDs do not depend on remembering anything each day, so they are not affected by user error, and their failure rate in real life is very low.

• With a hormonal IUD, the yearly pregnancy rate is about 0.1-0.2%.
• With a copper IUD, the yearly pregnancy rate is about 0.6-0.8%; protection in the first year is above 99%.

No birth control method gives complete protection, but with IUDs the difference between typical use and perfect use is very small.

Myths and the Facts

"Women who have never given birth cannot use an IUD."

Fact: According to the guidelines of organizations such as the World Health Organization and ACOG, an IUD can be used safely in young women and in women who have never given birth (nulliparous women). Smaller models suited to the size of the uterus are also available.

"An IUD causes infections and leads to infertility."

Fact: Current IUDs do not themselves cause lasting pelvic infection (infection of the organs inside the pelvis) or infertility. The risk of infection rises very slightly only in the first 20 days or so after insertion, and this comes not from the device but from bacteria in the vagina being carried upward during insertion. After that, the risk is similar to that of the general population. The real cause of infertility is untreated sexually transmitted infections such as chlamydia and gonorrhea. Because a hormonal IUD thickens the mucus at the cervix, it can make it harder for infections to travel upward.

"An IUD causes cancer."

Fact: On the contrary, studies show that using either a copper or a hormonal IUD lowers the risk of cancer of the lining of the uterus (endometrium) and cancer of the cervix. A hormonal IUD is also used in the treatment of some thickening of the uterine lining.

"It is very painful to insert and is felt during intercourse."

Fact: You may feel mild to moderate cramping for a few minutes during insertion. A simple painkiller taken half an hour to an hour before the procedure, or local numbing, reduces this feeling markedly. A correctly placed IUD sits inside the uterine cavity and is not felt during intercourse. Only the control strings that hang from the cervix into the vagina can rarely be felt by a partner; in that case, shortening the strings is enough.

"A hormonal IUD causes weight gain."

Fact: In clinical studies, no significant difference in weight gain was found between users of a hormonal IUD and users of a copper IUD or an inactive medicine. The hormone released acts locally.

"An IUD causes ectopic pregnancy."

Fact: Because an IUD prevents the great majority of pregnancies, it lowers a woman's overall risk of ectopic pregnancy compared with an unprotected woman. However, if a pregnancy does occur with an IUD in place, even though this is about 1 in 1,000, that pregnancy is more likely than other pregnancies to be ectopic and must always be assessed by a doctor.

"An IUD gets lost in the body and wanders through the organs."

Fact: The device can fall out on its own (1-10% of cases), most often in the first months, together with a period. Perforation of the wall of the uterus is very rare, occurring in fewer than 1 in 1,000 insertions in experienced hands.

What If You Become Pregnant With an IUD?

• Ectopic pregnancy is ruled out first.
• If the pregnancy is inside the uterus and is to be continued, the IUD is gently removed as early as possible if the control strings are visible. Removing it markedly lowers the risk of miscarriage, preterm birth and infection.

When and How Is It Inserted?

It can be inserted on any day of the menstrual cycle when you are sure you are not pregnant. The first 5-7 days of a period are a suitable time, because the cervix is softer and it is certain that there is no pregnancy.

The procedure includes the following steps:

• The cervix is viewed with a speculum (an instrument that opens the vagina) and cleaned with an antiseptic solution.
• The position and size of the uterus are assessed by hand, and the depth of the uterine cavity is measured with a thin instrument.
• The IUD is placed in the uterine cavity inside a thin applicator.
• The control strings are cut so that about 2-3 cm remain beyond the cervix.

The procedure is done in the clinic and takes a short time. At the end of the first period or after 4-6 weeks, the strings and the position of the device are checked with an exam and ultrasound.

What Are the Side Effects?

• Copper IUD: In the first 3-6 months, heavier periods, longer periods, spotting and a slight increase in period cramps may be seen.
• Hormonal IUD: Irregular spotting is common in the first 3-6 months. From the sixth month, bleeding falls markedly; in roughly one in five to one in two users, periods may stop completely within 1-2 years (amenorrhea). This is harmless and does not harm the ovaries.

When Should You See a Doctor?

• Severe, sharp or increasing pain in the groin and lower abdomen
• Foul-smelling vaginal discharge, high fever or chills
• Not being able to feel the control strings, strings that are clearly longer, or feeling the hard plastic body of the device at the vaginal opening
• A delayed period or suspicion of pregnancy
• Dizziness, weakness or very heavy bleeding that may lead to anemia

Who Cannot Use It?

An IUD of any type is not used in the following cases:

• Known or suspected pregnancy
• A pelvic infection now or in the past 3 months
• An infected cervix or active chlamydia or gonorrhea
• A serious infection after birth or after a miscarriage in the past 3 months
• Abnormal vaginal bleeding whose cause has not been investigated
• A diagnosis or suspicion of cancer of the uterus or cervix
• Large fibroids that clearly distort the uterine cavity, or inborn abnormalities of the uterus

A copper IUD is also not suitable with a copper allergy or Wilson's disease, and a hormonal IUD is not suitable with breast cancer or serious liver disease.

How Long Does It Stay? Can You Get Pregnant After Removal?

• Copper IUD: Gives protection for up to 10 years.
• Hormonal IUD: Effective for 3 to 8 years, depending on the type.

Removal is done in the clinic in seconds by gently pulling the strings that hang from the cervix with a special forceps. Protection ends the moment it is removed and fertility returns right away. Within 1 year after removal, pregnancy rates (85-90%) are the same as in women who have never used any method.

Breastfeeding and After Birth

Both copper and hormonal IUDs can be used while breastfeeding; they do not harm the amount or quality of milk or the baby's development. Because they contain no estrogen, they do not raise the risk of blood clots in the veins after birth.

Timing of insertion after birth can be planned in two ways:

• Right after birth: It can be inserted within the first 10-100 minutes after the placenta (afterbirth) is delivered, or during a cesarean. At this early time, the chance of the device falling out is slightly higher.
• 4-6 weeks after birth: When inserted at the postpartum check-up, the chance of falling out is lowest because the uterus has returned to its usual size.

Frequently Asked Questions

Do I need a check-up after the IUD is inserted?

Yes. At the end of the first period or 4-6 weeks after insertion, an exam and ultrasound are recommended to check the strings, confirm the position of the device and look for infection or falling out.

Does an IUD have to be replaced every year?

No. Devices stay in place for years depending on the type. When the time is up, it is removed or a new one is placed.

Will my partner notice that I have an IUD?

A correctly placed IUD is not felt during intercourse. If a partner rarely feels the control strings, the doctor can shorten them.