Intrauterine contraception

01Purpose and principlesWhat the treatment does and how it fits into care.

Copper devices release ions toxic to sperm and ova and work immediately when correctly positioned. Greater copper surface area and licensed duration vary by product. Copper often increases menstrual bleeding and pain, which matters for people with anaemia or dysmenorrhoea. It is the most effective emergency contraception and can remain as ongoing contraception.

LNG-IUD dose matters. A 52mg device has evidence-supported contraceptive use to eight years, while lower-dose 19.5mg and 13.5mg products have five- and three-year durations. A contraceptive licence does not automatically extend treatment of heavy menstrual bleeding or protection of the endometrium during systemic oestrogen therapy. Record dose, product, insertion date, insertion age and indication.

Insertion is a procedure requiring consent, analgesia options and pregnancy exclusion. Uterine perforation may be recognised immediately or later through missing threads. Expulsion is more common after immediate postpartum placement. Infection risk relates mainly to an STI present at insertion rather than persistent contamination by the device.

Key points

A copper IUD prevents fertilisation without hormone and can also provide emergency contraception; LNG-IUDs thicken cervical mucus and suppress endometrium, with dose-specific bleeding benefits and durations.
For contraception, any 52mg LNG-IUD inserted before age 45 is supported for up to eight years; when inserted at age 45 or older it can remain for contraception until age 55.
The eight-year 52mg extension is contraceptive only. Follow current product or professional duration for heavy menstrual bleeding and five-year endometrial protection with oestrogen therapy; 19.5mg and 13.5mg devices retain five- and three-year contraceptive durations.
Before removal, assess intercourse in the preceding seven days and arrange bridging or delayed removal to avoid pregnancy after sperm survives beyond device withdrawal.
Pregnancy is rare with an IUD, but if it occurs assess location urgently because the proportion that is ectopic is higher; management of threads and removal follows pregnancy-location and viability review.
Insertion-related perforation and expulsion are uncommon. Postpartum and breastfeeding contexts alter timing, expulsion and perforation counselling rather than creating a universal prohibition.
Routine antibiotic prophylaxis is not indicated for every insertion; assess STI risk, test where appropriate and treat infection without inventing a long delay for an asymptomatic low-risk patient.

02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.

Expected bleeding effect

Copper can increase bleeding and cramping, while a 52mg LNG-IUD commonly reduces bleeding and may cause initial irregular spotting.

Possible expulsionRed flag

New thread length, feeling plastic, return of bleeding or pregnancy symptoms can indicate partial or complete expulsion.

Possible perforationRed flag

Severe insertion pain, absent threads or an extrauterine device on imaging requires localisation before any removal attempt.

Pregnancy with IUCRed flag

Positive testing, pain or bleeding requires urgent ectopic assessment and specialist management of the device.

Pelvic infectionRed flag

Fever, lower abdominal pain, purulent discharge or cervical excitation needs prompt STI and sepsis assessment.

Red flags requiring action

Any pregnancy with IUC in situ requires prompt location assessment; pain, shoulder-tip pain, syncope or bleeding raises immediate ectopic concern.
Severe insertion pain, inability to sound normally, absent threads or a device seen outside the cavity suggests perforation or malposition; do not attempt blind removal.
Fever, pelvic tenderness and discharge after insertion require infection assessment, while the background STI risk must be distinguished from the device itself.
A 52mg LNG-IUD has an eight-year contraceptive duration when inserted before age 45, but that extension does not apply to heavy menstrual bleeding or endometrial protection.
Postpartum insertion is UKMEC 1 from birth to 48 hours, category 3 from 48 hours to under four weeks, category 1 from four weeks and category 4 with postpartum sepsis.

03Assessment before treatmentTests and checks that guide safe selection.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Pregnancy assessmentFirst step
Why
Reasonably exclude pregnancy before insertion and identify pregnancy when symptoms or device failure occur.
Interpretation and limitations
An early negative urine test can miss recent conception; date follow-up testing from the last unprotected sex.
02
Bimanual and speculum examination
Why
Assess uterine position, cervical findings, threads and signs of infection with informed consent.
Interpretation and limitations
Examination guides insertion and retrieval but cannot alone prove fundal device location or exclude ectopic pregnancy.
03
Transvaginal ultrasound
Why
Locate an IUD when threads are missing and assess pregnancy location or malposition.
Interpretation and limitations
If the device is not seen in the uterus, abdominal or pelvic radiography may be required to distinguish expulsion from perforation.
04
Site-based STI testing
Why
Detect gonorrhoea or chlamydia according to symptoms, age and exposure before or at insertion.
Interpretation and limitations
Testing can occur without routine delay in asymptomatic people; positive results need treatment and partner management.

04Treatment approachPreparation, options, escalation and aftercare.

01Insertion pathwayMatch device to goal and uterusFirst stepA patient chooses IUC for contraception, bleeding treatment or emergency use.

1Record pregnancy risk, STI context, uterine anatomy, bleeding goals, contraindications and the exact device dose and indication.
2Explain analgesia, insertion steps, perforation, expulsion, bleeding change, infection symptoms and product-specific duration.
3Insert with aseptic technique and consent, document uterine sounding, product, batch, date, threads and the replacement or review date.

02Missing-thread pathwayExclude pregnancy and locate before retrievalThreads cannot be seen or a user reports changed thread length.

1AlternativeAdvise alternative contraception or abstinence, perform pregnancy testing and assess recent intercourse for EC.
2Use ultrasound to locate the device; if absent from the uterus, obtain appropriate radiography rather than assuming expulsion.
3Arrange trained removal for malposition or perforation and do not instrument blindly when the location is unknown.

03Pregnancy pathwayLocate pregnancy before device decisionsA pregnancy test is positive with copper or LNG IUD in situ.

1Assess haemodynamic stability, pain and bleeding, obtain urgent pregnancy-location evaluation and treat rupture as an emergency.
2When intrauterine pregnancy continues and threads permit safe early removal, discuss reduced miscarriage and infection risk versus removal-related risk with specialist advice.
3If the device cannot be removed safely, provide high-risk obstetric follow-up and clear warning symptoms.

05Regimens, contraindications and interactionsTreatment details and the circumstances that modify them.

Provides hormone-free long-acting and emergency contraception with immediate effect after correct placement.

Copper intrauterine device

Insert the selected licensed copper device once into the uterine cavity and retain for its product duration, emergency indication or supported age-at-insertion extension.

May increase bleeding or pain; exclude pregnancy, assess infection and uterine distortion, and respond urgently to perforation or ectopic symptoms.

Provides highly effective contraception and substantial endometrial suppression that can treat heavy bleeding.

52mg levonorgestrel intrauterine device

Insert once; use for up to eight years for contraception when inserted before age 45, or until age 55 if inserted at age 45 or older, while applying shorter indication-specific treatment durations.

Do not transfer the eight-year contraceptive duration to endometrial protection or every bleeding indication; record product, dose, age and purpose.

06Complications, monitoring and follow-upAdverse effects, response and longer-term review.

Teach how to recognise expulsion, pregnancy, infection and perforation symptoms and provide a direct urgent contact route.
Track the device by dose, brand, insertion date, insertion age and indication rather than writing coil without a replacement date.
Investigate new pelvic pain, pregnancy symptoms, heavy bleeding or missing threads promptly and maintain contraceptive cover during localisation.
Before removal or replacement, review intercourse during the preceding seven days, pregnancy risk and bridging.

07Special situationsVariants, exceptions and circumstances that change the usual approach.

Dose predicts duration

A 52mg, 19.5mg and 13.5mg LNG-IUD cannot share one replacement clock.

Indication changes the clock

Contraception, heavy bleeding and endometrial protection have different evidence and licensing periods even for the same device.

Missing threads need localisation

Ultrasound followed by radiography when needed distinguishes retracted threads, expulsion and extrauterine perforation.

Ectopic risk is conditional

IUC lowers absolute ectopic pregnancy risk, but pregnancy despite IUC has a greater relative chance of being ectopic.

08Common pitfallsFrequent interpretation and management errors.

01
Calling every LNG-IUD Mirena and applying an eight-year duration.
02
Removing a device after recent intercourse without pregnancy-risk planning.
03
Attempting blind retrieval when threads are missing and location is unknown.
04
Ignoring ectopic pregnancy because the patient has contraception.
05
Using postpartum sepsis as a setting for immediate insertion.

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