Everything you need to know before getting an IUD

The intrauterine device (IUD) is one of the most effective reversible contraceptive methods available. It is a small T‑shaped device placed inside the uterus by a qualified clinician. IUDs offer long‑acting, low‑maintenance contraception and are used by people across a wide range of ages and reproductive histories. Before choosing an IUD it is important to understand the types available, how they work, who is an appropriate candidate, what to expect during insertion and afterward, potential risks and complications, and follow‑up care. This article summarizes current clinical guidance and evidence to help you make an informed decision. (Sources: ACOG, NIH/MedlinePlus, Mayo Clinic, Cleveland Clinic)

How effective are IUDs?

IUDs are among the most effective reversible contraceptives, with typical‑use pregnancy rates of less than 1% per year for both hormonal and copper devices. Effectiveness is comparable to sterilization but is fully reversible when the device is removed. Long‑acting reversible contraception (LARC) such as IUDs is associated with lower rates of unintended pregnancy compared with short‑acting methods because it does not rely on ongoing user adherence. (ACOG, Mayo Clinic)

Types of IUDs

There are two principal classes of IUDs used in clinical practice:

Hormonal IUDs (levonorgestrel‑releasing intrauterine systems)
Examples: Mirena, Liletta, Kyleena, Skyla (brand names and available durations vary by product and country).
Mechanism: Release a low dose of levonorgestrel locally into the uterine cavity. They primarily thicken cervical mucus, inhibit sperm transport, and create an endometrial environment less favorable to implantation. They may also suppress ovulation in some users.
Duration: Typically effective for 3 to 8 years depending on the specific product; most commonly 3–5 years for smaller devices and up to 8 years for certain higher‑dose products (refer to product labeling).

Copper IUDs (non‑hormonal)
Example: ParaGard (copper intrauterine device).
Mechanism: Copper ions released from the device create an intrauterine environment that is toxic to sperm and prevents fertilization; they may also induce a local inflammatory response in the endometrium that reduces the likelihood of implantation.
Duration: Approved for up to 10–12 years depending on the device.

Both hormonal and copper IUDs include a flexible frame and one or more thin strings that extend through the cervical canal into the upper vagina. These strings are used by clinicians to confirm placement and to remove the device when desired.

(References: ACOG Practice Bulletin; Mayo Clinic; Cleveland Clinic)

How IUDs work (mechanism of action)

Hormonal IUDs: Levonorgestrel released locally causes cervical mucus to thicken, which reduces sperm penetration. It also thins the endometrial lining and alters uterine contractility, making fertilization and implantation unlikely. Systemic absorption is minimal compared with oral hormonal contraception.

Copper IUDs: Copper ions impair sperm motility and viability and create a local inflammatory response within the uterine cavity that is inhospitable to sperm and fertilization.

Both device types primarily prevent fertilization; neither is indicated to terminate an existing pregnancy.

(References: ACOG; NIH/MedlinePlus)

Who is a good candidate?

IUDs are appropriate for many reproductive‑aged people, including adolescents and those who have not had children. Major groups who frequently choose IUDs include:

Individuals seeking reliable, long‑term reversible contraception.
People who prefer to avoid daily or frequent contraceptive action.
Those who cannot or prefer not to use continuous systemic hormonal contraception.
Breastfeeding persons (timing of insertion may vary — see postpartum section).

ACOG and other professional societies support offering IUDs to eligible adolescents and nulliparous individuals. Suitability should be determined in consultation with a clinician, taking into account medical history, preferences, and any contraindications. (ACOG, CDC)

Contraindications and precautions

Absolute contraindications to IUD insertion commonly include:

Current pregnancy.
Known or suspected pregnancy of unknown location.
Active pelvic inflammatory disease (PID) or untreated cervicitis.
Current purulent cervicitis or chlamydial/gonorrheal infection until treated.
Recent postpartum sepsis or endometritis.
Known or suspected uterine or cervical malignancy.
Unexplained abnormal uterine bleeding until evaluated.
Uterine cavity anomalies that distort the uterine cavity (significant fibroids, congenital anomalies) which may prevent correct placement.

Relative contraindications or situations requiring individualized counseling:

History of repeated pelvic infections — benefits versus risks should be discussed.
Prior uterine surgery (e.g., cesarean section) — insertion may still be safe but requires clinician assessment.
Known allergy to copper or Wilson disease (for copper IUDs) — copper IUDs are contraindicated.
Vaginal bleeding of unknown cause — evaluate before insertion.

Clinicians will screen and evaluate based on medical history, pregnancy testing when indicated, and may perform STI screening according to guidelines. (ACOG, NIH/MedlinePlus, CDC)

Pre‑insertion evaluation and counseling

Before inserting an IUD, clinicians typically:

Conduct a comprehensive medical and contraceptive history and informed consent discussion that covers risks, benefits, alternative options, expected side effects, and what to do if problems occur.
Perform a targeted pelvic exam if indicated. Routine bimanual exam may be performed, but it is not required for all patients.
Offer or perform screening for sexually transmitted infections if risk factors are present or per local protocols; many clinics follow CDC or local guidance for STI screening prior to insertion.
Perform a pregnancy test if there is any possibility of pregnancy or if the timing of the menstrual cycle is uncertain.
Discuss pain management options during insertion (see below).
Provide instructions on what to expect after insertion, including normal symptoms and warning signs that require prompt evaluation.

Counseling should be patient‑centered and include information about changes in bleeding patterns, potential side effects, and how to check strings. (ACOG, Mayo Clinic, Cleveland Clinic)

The insertion procedure

Insertion is an outpatient procedure performed by trained clinicians (gynecologists, family planning clinicians, or other providers credentialed in IUD insertion). Key points:

Timing: IUDs may be inserted at any point in the menstrual cycle if pregnancy can be reasonably excluded. Many clinicians prefer to insert during the menses or when pregnancy is unlikely; postpartum timing depends on clinical context.
Procedure steps: The clinician examines the cervix and vagina, cleans the cervix, stabilizes the uterus with a tenaculum, measures uterine depth with a sound, and then advances the IUD through the cervical canal into the uterine cavity. Strings are trimmed to an appropriate length. The procedure typically takes only a few minutes.
Pain management: Many people experience cramping or discomfort during and after insertion. Options to reduce discomfort include pre‑procedure oral analgesics (ibuprofen or naproxen), local cervical anesthesia (paracervical block), and cervical priming with misoprostol in selected situations. Anxiety‑relief strategies and procedural explanations can improve tolerance.
Immediate post‑procedure: Observation for a short period may follow insertion. Heavy bleeding or severe pain immediately after insertion is uncommon and should be assessed.

The clinician will document the device type, lot/serial number, and insertion date in the health record. (ACOG, Cleveland Clinic, Mayo Clinic)

Pain during insertion — what to expect

Pain perception varies. Some individuals report only mild cramping similar to menstrual cramps, while others describe moderate or more intense discomfort. Risk factors for increased insertion pain include nulliparity (not having given birth), anxiety, and difficult cervical manipulation. Use of oral nonsteroidal anti‑inflammatory drugs (NSAIDs) before the procedure may reduce immediate cramping; some clinics provide local anesthesia for those at higher risk of significant discomfort. Discuss pain management options with your clinician beforehand. (ACOG, Mayo Clinic)

What to expect in the days and months after insertion

The first few days to weeks: Cramping and light to moderate bleeding or spotting are common for several days to weeks after insertion. Pain usually diminishes over the first week.
Hormonal IUDs: Many users experience lighter periods over time; some develop amenorrhea (absence of bleeding) after several months. Spotting and irregular bleeding are common in the first 3–6 months. Other systemic side effects (e.g., mood changes, breast tenderness, acne) are possible but are generally less common than with systemic hormonal methods because levonorgestrel is released locally at low systemic levels.
Copper IUDs: Users commonly experience heavier menstrual bleeding and increased cramping, especially in the first 3–6 months. Over time some users find bleeding patterns return to baseline, but some will have persistently heavier and longer periods compared with pre‑insertion.
Ovarian cysts: Some users of levonorgestrel IUDs may develop functional ovarian cysts; most are benign and resolve without intervention but occasionally require evaluation.

Any new, severe, or persistent symptoms should prompt clinical evaluation. (ACOG, Mayo Clinic, Cleveland Clinic)

Efficacy in special situations

Adolescents and nulliparous people: IUDs are effective and appropriate with no requirement to have had prior pregnancies.
Postpartum and postpartum lactation: IUDs may be placed immediately postpartum (within 10 minutes of placental delivery) or delayed (e.g., at the 6‑week visit). Immediate postpartum insertion carries a higher expulsion risk than delayed insertion but is a reasonable option for many who desire a LARC method before hospital discharge. Hormonal IUDs are compatible with breastfeeding; systemic hormonal exposure is low and generally considered safe. (ACOG)
Emergency contraception: Copper IUD placement within five days of unprotected intercourse is the most effective method of emergency contraception and also provides ongoing contraception thereafter. (ACOG, CDC)

Removal and return to fertility

Removal is a brief clinical procedure performed by a trained provider. Once the IUD is removed, fertility typically returns rapidly to baseline; many individuals are able to conceive within one menstrual cycle. There is no evidence that long‑term use of an IUD adversely affects long‑term fertility for most people. If pregnancy is not desired immediately after removal, effective contraception should be started prior to removal or at the time of removal, depending on the method selected. (ACOG, NIH/MedlinePlus)

Risks and complications

IUDs are generally safe, but there are potential risks that you should understand:

Expulsion: Partial or complete expulsion (device coming out of the uterus) occurs most frequently in the first months after insertion. Expulsion rates vary by device type, timing of insertion (higher with immediate postpartum insertion), and individual factors; reported rates are roughly 2–10% in the first year in many studies. If expulsion occurs, pregnancy may result if intercourse has occurred; do not attempt to reinsert the device yourself—seek clinical evaluation. (Mayo Clinic, ACOG)

Uterine perforation: Rarely, the IUD can perforate the uterine wall during insertion. Perforation rates are low (on the order of approximately 1 per 1,000 insertions, though exact rates vary by study and clinician experience). If perforation is suspected (severe or atypical pain, inability to locate strings, or abnormal imaging), imaging and appropriate management are required. (ACOG, Cleveland Clinic)

Infection: Insertion does not cause chronic pelvic inflammatory disease (PID). The greatest risk of PID is associated with the presence of an untreated sexually transmitted infection at the time of insertion. The risk of infection is highest in the first 20 days after insertion and is low overall thereafter. Screening for STIs and treating infections before insertion reduces this risk. (ACOG, CDC)

Pregnancy with an IUD in place: Pregnancy is uncommon while an IUD is in place; however, if pregnancy occurs, there is an increased relative proportion of ectopic pregnancies among pregnancies that do occur. If pregnancy occurs with an IUD in place, prompt evaluation is necessary because of the risk of complications, and removal of the IUD may be recommended if strings are visible and removal is feasible. (ACOG, NIH)

Other adverse effects: Changes in bleeding patterns, mood changes, acne, breast tenderness, or headaches may occur, particularly with hormonal IUDs. Copper devices may increase menstrual bleeding and cramping.

Discuss individualized risks with your clinician. Many of the risks are low in absolute terms, and for many people the benefits outweigh risks. (Mayo Clinic, Cleveland Clinic, ACOG)

How to check strings and what to do if strings feel different

Most clinicians instruct users to feel for the IUD strings periodically, such as after each menstrual period. The strings are typically felt at the top of the vagina near the cervix. If you cannot feel the strings, if strings are shorter or longer than expected, or if you or your provider feel the device at the cervix, contact your clinician. Do not pull on the strings; do not attempt to remove or reposition the IUD yourself. If strings are missing, the clinician may perform a pelvic exam and possibly ultrasound to confirm intrauterine placement. If the IUD has been expelled or is no longer in the uterus, pregnancy protection will be lost.

When to seek medical attention

Contact your clinician promptly if you experience:

Fever, chills, or foul‑smelling vaginal discharge (may signal infection).
Severe abdominal or pelvic pain that is not relieved by over‑the‑counter analgesics.
Heavy vaginal bleeding (soaking more than one pad per hour for several hours).
Sudden disappearance or inability to feel the IUD strings.
Signs of pregnancy (missed period, positive pregnancy test) or if pregnancy is suspected.
Persistent or worsening symptoms after insertion.

Early evaluation helps prevent complications and ensures appropriate management. (Mayo Clinic, Cleveland Clinic)

IUDs and sexually transmitted infections (STIs)

IUDs do not protect against STIs. If you or your partner(s) are at increased risk for STIs, condoms or other barrier methods should be used in addition to an IUD. Clinicians commonly recommend STI screening based on individual risk factors and local guidelines prior to insertion. (CDC, ACOG)

Special clinical considerations

Breastfeeding: Both copper and levonorgestrel IUDs are considered safe for breastfeeding individuals. Timing of insertion after delivery varies; immediate postpartum insertion is an option with counseling regarding expulsion risk, and delayed insertion is commonly performed at or after 6 weeks postpartum.

Immunocompromised patients: Generally, IUDs may be offered but require individualized counseling and follow‑up due to altered infection risks.

Wilson disease or copper allergy: Copper IUDs are contraindicated.

Use with anticoagulants: People on anticoagulation can typically use IUDs, but consult with a clinician about bleeding risks and management.

(ACOG, Mayo Clinic)

IUDs as emergency contraception

A copper IUD placed within five days after unprotected intercourse is the most effective form of emergency contraception and provides ongoing contraception. It is appropriate for those who desire long‑term contraception after a single unprotected event. Hormonal IUDs are not routinely used as emergency contraception, though some clinicians may consider options per protocol; current evidence supports copper IUDs for emergency use. (ACOG, CDC)

Follow‑up care

Short‑term check: Many clinicians recommend a follow‑up appointment 4–6 weeks after insertion to assess symptoms and confirm device position if clinically indicated. Routine ultrasound after insertion is not required for all users but may be performed if there is concern for malposition, missing strings, or persistent symptoms.

Long‑term: Annual well‑person or contraceptive visits are appropriate. A clinician should evaluate any new pelvic pain, heavy bleeding, or inability to feel strings.

Removal: The IUD can be removed at any time by a trained clinician. If removal is desired to attempt conception, fertility typically returns quickly. If replacement is desired, another device can often be inserted at the same visit.

(ACOG, Cleveland Clinic)

Cost, access, and insurance

IUDs have a higher up‑front cost than short‑acting methods but are cost‑effective over time. Many private insurance plans and public programs cover IUDs with no or low cost‑sharing, depending on local laws and payer policies. Title X clinics, community health centers, and family planning clinics may provide IUDs at reduced cost. Discuss cost and coverage with your clinician or clinic staff before the visit.

Discussing choice with your clinician — questions to ask

When considering an IUD, it may be helpful to ask your clinician:

Which IUD type do you recommend for my medical history and preferences?
What are the expected changes to my menstrual bleeding pattern?
How long will this IUD last, and what is the replacement schedule?
What pain management options are available during insertion?
What are the signs of complications that should prompt me to seek care?
How and when will the device be removed, if I decide to stop using it?
Does insurance cover the device and insertion, and are there lower‑cost options?

A clear, patient‑centered discussion will help you select the method that best aligns with your health needs and preferences. (ACOG, Mayo Clinic)

Myths and misconceptions

Myth: IUDs cause long‑term infertility. Evidence does not support this. For most people, fertility returns promptly after removal.
Myth: Only people who have given birth can use IUDs. Current guidelines support use in nulliparous individuals.
Myth: IUDs cause widespread systemic hormonal effects. Levonorgestrel IUDs release low levels of hormone locally; systemic effects are generally minimal compared with oral hormonal methods, though some users may experience systemic symptoms.

Reliable counseling from a clinician can address specific concerns and correct misconceptions. (ACOG, NIH/MedlinePlus)

Summary — is an IUD right for you?

IUDs provide highly effective, long‑acting, reversible contraception with options for both hormonal and non‑hormonal management. They are appropriate for many people, including adolescents, nulliparous individuals, and those who are breastfeeding. Choice of device depends on individual priorities: hormonal IUDs often reduce menstrual bleeding and may be preferred for those with heavy menstrual bleeding or who prefer fewer menses; copper IUDs are hormone‑free and may be preferred by those who wish to avoid hormones or who want emergency contraception capability.

Risks such as expulsion, perforation, and infection are uncommon, and many risks are minimized with appropriate screening, technique, and follow‑up care. Discuss your medical history, preferences, and any concerns with a trained clinician to determine whether an IUD is an appropriate method for you and to plan timing, insertion, and follow‑up.

For further reading and patient resources, reputable clinical sources include the American College of Obstetricians and Gynecologists (ACOG), NIH/MedlinePlus, Mayo Clinic, and Cleveland Clinic. Your clinician can provide the most applicable recommendations for your individual health needs.

References

American College of Obstetricians and Gynecologists (ACOG). Practice Bulletin and Committee Opinions on intrauterine contraception and long‑acting reversible contraception. https://www.acog.org
NIH / MedlinePlus. Intrauterine Devices (IUDs). https://medlineplus.gov/intrauterinedevices.html
Mayo Clinic. IUD (Intrauterine Device). https://www.mayoclinic.org/tests-procedures/iud/about/pac-20384717
Cleveland Clinic. Intrauterine Device (IUD). https://my.clevelandclinic.org/health/treatments/10957-intrauterine-device-iud

(These references provide patient‑level and clinical guidance; consult your clinician for personalized medical advice.)