Intrauterine Contraceptive Devices

Intrauterine contraceptive devices (IUCDs) are long-acting reversible contraceptives (LARC) placed inside the uterine cavity. They divide cleanly into two families — the copper-bearing (non-hormonal) devices and the levonorgestrel-releasing (hormonal) intrauterine system (LNG-IUS). For NEET PG, the highest-yield areas are the mechanism of the copper IUD, ideal timing of insertion, LNG-IUS non-contraceptive benefits, and the complications/contraindications list.

Classification

IUCDs are broadly classified by their pharmacological activity and generation.

Category	Examples	Active agent	Duration of use
First-generation (inert/non-medicated)	Lippes loop, Margulies coil	None (polyethylene)	Largely obsolete
Second-generation (copper)	Cu-T 380A (Paragard), Cu-T 200, Multiload Cu-250/375, Nova-T	Copper	Cu-T 380A: 10 years
Third-generation (hormonal)	LNG-IUS 52 mg (Mirena), LNG-IUS 19.5 mg (Kyleena), LNG-IUS 13.5 mg (Skyla/Jaydess)	Levonorgestrel	Mirena: 5–8 years
Frameless	GyneFix	Copper sleeves on a thread anchored to fundus	~5–10 years

High-yield: The Cu-T 380A is the gold-standard copper IUCD — it carries 380 mm² of copper (314 mm² on the vertical stem + 33 mm² on each transverse arm as copper sleeves/collars), is the most effective copper device, and is approved for 10 years (effective up to 12 years in WHO data).

Mechanism of Action

The mechanism differs fundamentally between the two device types, and this distinction is a recurring MCQ.

Copper IUCD

The copper IUD is primarily spermicidal — it does not act mainly by preventing implantation.

Copper ions released into uterine/tubal fluid → sterile inflammatory ("foreign-body") endometrial reaction → cytotoxic to sperm + impaired sperm motility and capacitation → phagocytosis of sperm → prevention of fertilisation.

Key points:

• Copper ions are toxic to spermatozoa and to the ovum, impairing sperm transport and viability before fertilisation occurs.
• The endometrial inflammatory exudate (macrophages, leucocytes, prostaglandins) creates a hostile environment.
• Copper alters cervical mucus and endometrial enzymes/glycogen.
• An anti-implantation (blastotoxic) effect exists as a secondary/back-up mechanism — this is why the copper IUD is the most effective method of emergency contraception when inserted within 5 days.

High-yield: The copper IUD's principal action is prevention of fertilisation (spermicidal), not prevention of implantation. It is not an abortifacient.

LNG-IUS (Mirena)

The hormonal system releases ~20 µg of levonorgestrel/day initially.

Local progestin → marked endometrial atrophy/decidualisation + thickening of cervical mucus (blocks sperm penetration) → suppression of sperm capacitation/survival → variable/inconsistent ovulation suppression.

• The dominant contraceptive effects are cervical mucus thickening and endometrial suppression.
• Ovulation is suppressed in only a minority of cycles (≈25%), so most women continue to ovulate — this preserves ovarian function and explains rapid return of fertility.
• Endometrial atrophy is responsible for the dramatic reduction in menstrual blood loss.

Efficacy

Both modern devices are top-tier LARCs with first-year failure rates well under 1%, rivalling sterilisation.

Device	Perfect-use failure (1st yr)	Typical-use failure	Duration
Cu-T 380A	~0.6%	~0.8%	10 yrs
LNG-IUS 52 mg (Mirena)	~0.2%	~0.2%	5–8 yrs
Female sterilisation	~0.5%	~0.5%	Permanent

High-yield: The LNG-IUS (Mirena) is more effective than female sterilisation in the first year, with a Pearl Index around 0.1–0.2.

Ideal Timing of Insertion

Timing is one of the most reliably tested facts.

Situation	Ideal time of insertion
Routine/interval	During or just after menstruation (first few days of cycle) — cervix is soft/patulous, pregnancy is excluded, bleeding masks spotting. Can be inserted any time if reasonably certain not pregnant.
Postpartum	Within 10 minutes of placental delivery (immediate postplacental) OR after 6 weeks (delayed). Insertion between 48 h and 4 weeks carries the highest expulsion risk and is avoided.
Post-abortion	Immediately after a first-trimester abortion (uncomplicated).
Post-caesarean	Intra-caesarean (at the time of section) or after 6 weeks.
Emergency contraception	Copper IUD within 5 days (120 h) of unprotected intercourse — the most effective EC method.
Lactation	Can be inserted; preferred 6 weeks postpartum.

High-yield: Best routine timing = during or within the first week of menstruation. Postpartum, the ideal windows are immediately postplacental (within 10 min) or after 6 weeks — the 4-week to 6-week interval has the highest expulsion rate.

A simple memory flow for the new acceptor: Confirm not pregnant → counsel/consent → bimanual exam (size, position, version) → asepsis → sound the uterus (≥6 cm) → load and insert via withdrawal/push technique → trim threads (~3 cm) → document.

Clinical Features / Expected Bleeding Pattern

The bleeding profile is the chief differentiator patients (and examiners) care about:

• Copper IUD: Tends to increase menstrual blood loss and dysmenorrhoea, especially in the first 3–6 months. Heavy menstrual bleeding (HMB) is the commonest medical reason for removal.
• LNG-IUS: Causes irregular spotting in the first 3–6 months, then progressively reduces flow; up to 20% develop amenorrhoea by 1 year. This is the basis for its therapeutic use in HMB.

Non-Contraceptive Benefits of LNG-IUS

This is a frequent NEET PG stem. The LNG-IUS is therapeutic far beyond contraception.

• Heavy menstrual bleeding (HMB/menorrhagia): First-line medical therapy — reduces blood loss by 70–95%; can avert hysterectomy.
• Dysmenorrhoea and endometriosis-associated pain.
• Adenomyosis — reduces bleeding and pain.
• Endometrial protection in women on oestrogen HRT (provides the progestogenic arm).
• Endometrial hyperplasia (without atypia) — treatment and prevention.
• Fibroids with HMB (non-distorting cavity).
• Reduces risk of PID (mucus plug) compared with copper, and lowers endometrial cancer risk.

High-yield: LNG-IUS is the first-line treatment for idiopathic heavy menstrual bleeding (NICE) and provides endometrial protection during oestrogen-only HRT.

Complications

Remember the mnemonic "PAINS" for warning signs prompting review: Period late/abnormal bleeding, Abdominal pain/dyspareunia, Infection/abnormal discharge, Not feeling well/fever/chills, String missing/longer/shorter.

1. Pain and bleeding

Most common early problem with copper devices; usually settles in 3–6 months. Persistent HMB is the leading cause of medical removal.

2. Expulsion

• Incidence ~2–10%, highest in the first year and first 3 months.
• Risk factors: nulliparity, immediate postpartum (4 wk–6 wk window), heavy menses, prior expulsion, malposition.

3. Perforation

• Rare (~1–2 per 1000 insertions); usually occurs at insertion.
• Risk factors: lactation, postpartum insertion, retroverted/anteflexed uterus, inexperienced operator.
• Suspected when threads disappear. Confirm location with USG; if not in uterus → X-ray/abdominal imaging. A translocated IUD is removed (often laparoscopically).

High-yield: Lactation is a recognised risk factor for uterine perforation during IUCD insertion.

4. Pelvic inflammatory disease (PID)

• Risk is transiently elevated only in the first ~20 days after insertion (introduction of organisms), then returns to baseline.
• Long-term IUCD use does not independently increase PID risk in low-STI-risk women.
• Actinomyces israelii may be seen on Pap smear in long-term users — if asymptomatic, no treatment/removal needed; treat only if symptomatic.

5. Pregnancy with IUCD in situ

• Overall ectopic risk is reduced (because total pregnancies fall), BUT if pregnancy occurs with an IUD in place, the proportion that are ectopic is higher — so always exclude ectopic in a pregnant IUD user.
• LNG-IUS users who conceive have a notably higher proportion of ectopic pregnancies.
• If intrauterine pregnancy occurs and threads are visible → remove the device (reduces septic abortion, preterm labour). If threads not seen and woman wants to continue → counsel re: risk of second-trimester septic abortion.

High-yield: IUCD decreases the absolute risk of ectopic pregnancy versus no contraception, but if a woman conceives with an IUCD in situ, ectopic must be ruled out because the relative proportion of ectopics is increased.

6. Missing threads

Causes (DDx) → pregnancy, expulsion, perforation/translocation, threads curled in canal, deep insertion. Approach: exclude pregnancy → speculum/cytobrush in canal → if not found, USG → if not in uterus, plain X-ray abdomen/pelvis.

7. Vasovagal syncope / cervical shock at insertion

Bradycardia and hypotension from cervical manipulation; managed with atropine and recumbency.

Contraindications (WHO MEC Category 3/4)

Absolute contraindications (Category 4) — both	Specific to copper	Specific to LNG-IUS
Known/suspected pregnancy	Wilson's disease	Current breast cancer (Cat 4)
Current PID/cervicitis (purulent) / active STI	Copper allergy	Active liver tumour/severe cirrhosis
Unexplained abnormal vaginal bleeding (undiagnosed)	Heavy menses/severe dysmenorrhoea (relative — choose LNG instead)	—
Distorted uterine cavity (large fibroids, bicornuate, severe stenosis)	—	—
Genital tract malignancy (cervical/endometrial)	—	—
Gestational trophoblastic disease with raised hCG	—	—
Pelvic TB (active genital tuberculosis)	—	—

High-yield: Wilson's disease and copper allergy specifically contraindicate the copper IUD (not the LNG-IUS). Active pelvic TB and distorted uterine cavity contraindicate both.

Notable points often misremembered:

• Nulliparity is NOT a contraindication — IUCDs (including LNG-IUS) are recommended LARCs for nulliparous and adolescent women.
• Past ectopic pregnancy is not an absolute contraindication (Cat 2 for copper).
• HIV-positive women may use IUCDs (Cat 2).
• Valvular heart disease/risk of endocarditis — IUCD use is acceptable; routine antibiotic prophylaxis at insertion is not recommended currently.

Key Differentials & Comparison

The single most examined comparison table:

Feature	Copper IUD (Cu-T 380A)	LNG-IUS (Mirena)
Active agent	Copper (380 mm²)	Levonorgestrel 52 mg (~20 µg/day)
Primary mechanism	Spermicidal / prevents fertilisation	Cervical mucus + endometrial suppression
Duration	10 (–12) years	5–8 years
Effect on menses	Increases flow & cramps	Decreases flow; ~20% amenorrhoea
Failure rate (1st yr)	~0.8%	~0.2%
Emergency contraception	Yes (≤5 days)	Generally not used for EC
Therapeutic use	None (may worsen HMB)	HMB, dysmenorrhoea, HRT cover, hyperplasia, endometriosis
Hormonal side effects	None	Spotting, breast tenderness, acne, mood (minimal systemic)
Specific contraindication	Wilson's disease, copper allergy	Current breast cancer
Return of fertility	Immediate	Rapid (next cycle)

Recently asked / exam angle

• Mechanism of action of copper IUD — answer: chiefly spermicidal / prevents fertilisation (foreign-body cytotoxic effect of copper ions), NOT mainly anti-implantation. Frequently set as a "which is the principal mechanism" MCQ.
• Copper content of Cu-T 380A = 380 mm²; effective for 10 years.
• Ideal time of insertion — during/just after menstruation; postpartum immediately postplacental or after 6 weeks.
• Most effective method of emergency contraception = copper IUD within 120 hours (5 days).
• LNG-IUS non-contraceptive benefit — first-line for heavy menstrual bleeding; also endometrial protection on HRT; reduces dysmenorrhoea.
• Risk factor for perforation = lactation / postpartum insertion.
• PID risk is raised only in the first ~20 days after insertion.
• Actinomyces on Pap smear in asymptomatic user → no action / leave the device (treat only if symptomatic).
• Pregnant woman with IUD in situ → rule out ectopic; if threads visible and intrauterine, remove the device.
• Wilson's disease → avoid copper IUD; LNG-IUS acceptable.
• Nulliparity is not a contraindication to IUCD (common trap).
• Highest expulsion risk = first year, and postpartum insertion in the 4-week–6-week window.

Rapid revision

1. Cu-T 380A = 380 mm² copper, lasts 10 years, most effective copper device.
2. Copper IUD works mainly by being spermicidal / preventing fertilisation, not by blocking implantation; it is not an abortifacient.
3. Copper IUD = best emergency contraceptive, effective up to 5 days (120 h) post-coitus.
4. LNG-IUS (Mirena) acts via cervical mucus thickening + endometrial atrophy; ovulation suppressed in only ~25% of cycles.
5. LNG-IUS is first-line for heavy menstrual bleeding and gives endometrial protection on oestrogen HRT.
6. Copper increases menstrual loss; LNG-IUS decreases it (≈20% amenorrhoea at 1 year).
7. Ideal insertion = during/just after menstruation; postpartum = immediately postplacental or ≥6 weeks.
8. Lactation raises the risk of uterine perforation at insertion.
9. PID risk rises only in the first ~20 days; thereafter back to baseline.
10. IUCD lowers absolute ectopic risk, but a pregnancy occurring with IUD in situ has a higher chance of being ectopic — always exclude it.
11. Missing threads → exclude pregnancy → USG → X-ray to locate a possibly perforated/translocated device.
12. Wilson's disease & copper allergy contraindicate copper IUD; nulliparity is NOT a contraindication; active pelvic TB and distorted cavity contraindicate both.