What are the differences between Mirena (levonorgestrel) and Liletta (levonorgestrel), Kyleena (levonorgestrel), Skyla (levonorgestrel), and Paragard (copper IUD) for a female patient of reproductive age seeking contraception or experiencing heavy menstrual bleeding?

IUD Comparison: Mirena/Liletta, Kyleena, Skyla, and Paragard

All five IUDs are highly effective long-acting reversible contraceptives with failure rates <1%, but they differ significantly in hormone content, duration of use, bleeding effects, and therapeutic indications. 1

Key Specifications

Hormonal IUDs (Levonorgestrel-releasing)

Mirena and Liletta (52 mg levonorgestrel):

• FDA-approved duration: 5 years (though Mirena data support up to 7 years of efficacy) 1
• Failure rate: 0.1% 1
• Bleeding pattern: Irregular menses initially, then progressive reduction in bleeding; many women develop amenorrhea 1, 2
• Menstrual blood loss reduction: 90% from baseline during first year 2
• Therapeutic indications: Both contraception AND treatment of heavy menstrual bleeding; Mirena also approved for endometrial protection during hormone replacement therapy 3
• Ideal candidates: Women with heavy menstrual bleeding, dysmenorrhea, adenomyosis, fibroids, or those requiring endometrial protection 3

Kyleena (19.5 mg levonorgestrel):

• FDA-approved duration: 5 years 1
• Failure rate: 0.1% 1
• Physical characteristics: Smaller 3.8-mm diameter inserter, particularly suitable for nulliparous women 3, 4
• Bleeding pattern: Less amenorrhea than Mirena/Liletta, but still reduced bleeding compared to baseline 3, 4
• Indication: Contraception only (not approved for heavy menstrual bleeding treatment) 3

Skyla (13.5 mg levonorgestrel):

• FDA-approved duration: 3 years 1
• Failure rate: 0.1% 1
• Physical characteristics: Smallest 3.8-mm diameter inserter, particularly suitable for nulliparous women 3, 4
• Bleeding pattern: Less amenorrhea than higher-dose options, but reduced bleeding compared to baseline 3, 4
• Indication: Contraception only 3

Non-Hormonal IUD

Paragard (Copper T380A):

• FDA-approved duration: 10 years (data support 12 years of efficacy) 1
• Failure rate: 0.8% 1
• Bleeding pattern: Regular menstrual cycles continue; expect heavier bleeding and more cramping, especially during first 3-6 months 1, 5
• Menstrual changes: Increased menstrual blood loss may persist even with long-term use 5
• Therapeutic use: Also approved for emergency contraception (within 5 days of unprotected intercourse) 6
• Ideal candidates: Women desiring hormone-free contraception, those with contraindications to hormones, or requiring emergency contraception 1, 6

Clinical Decision Algorithm

For contraception alone:

• Nulliparous women or those preferring smaller device: Choose Kyleena (5 years) or Skyla (3 years) due to 3.8-mm inserter 3, 4
• Parous women or those accepting standard inserter: Choose Mirena/Liletta (5 years) or Paragard (10 years) 4
• Hormone-free preference: Paragard is the only option 1

For heavy menstrual bleeding treatment:

• Only Mirena or Liletta are FDA-approved for this indication 3
• Kyleena and Skyla are NOT approved for heavy bleeding treatment despite containing levonorgestrel 3, 4

For dysmenorrhea:

• Any levonorgestrel IUD (Mirena, Liletta, Kyleena, Skyla) provides significant symptom improvement 1
• Paragard may worsen cramping 1

For emergency contraception:

• Both Paragard (copper) and levonorgestrel 52-mg IUDs are effective when inserted within 5 days of unprotected intercourse 6
• Levonorgestrel IUD is noninferior to copper IUD for emergency contraception (0.3% vs 0% pregnancy rate, difference 0.3 percentage points, 95% CI -0.9 to 1.8) 6

Critical Bleeding Management Differences

Levonorgestrel IUDs (all doses):

• First 2-3 months: Expect irregular spotting (common and not harmful) 2
• After 3-6 months: Progressive reduction in bleeding; 20-60% reduction in menstrual blood loss 7, 2
• Treatment if needed: NSAIDs for 5-7 days during bleeding episodes 7

Paragard (Copper IUD):

• First 3-6 months: Expect unscheduled spotting, light bleeding, heavy or prolonged bleeding (common and not harmful) 1
• Long-term: Increased menstrual bleeding may continue indefinitely 5
• Treatment if needed: NSAIDs for 5-7 days during bleeding episodes; tranexamic acid for persistent heavy bleeding 1, 7

Common Pitfalls to Avoid

Do not dismiss new-onset heavy bleeding without evaluation: Rule out IUD displacement, pregnancy (including ectopic), STIs, or new uterine pathology (polyps, fibroids) especially after the initial 3-6 month adjustment period 1, 7

Do not prescribe Kyleena or Skyla for heavy menstrual bleeding treatment: These are not FDA-approved for this indication; only Mirena or Liletta have this therapeutic indication 3, 4

Do not assume nulliparity is a contraindication: All IUDs are safe and appropriate for nulliparous women and adolescents 1, 5

Do not withhold IUDs from women at high STI risk: Screen on day of insertion and treat any identified STI without removing the IUD 1

Additional Levonorgestrel IUD Side Effects

Beyond bleeding changes, levonorgestrel IUDs may cause headaches, nausea, hair loss, breast tenderness, depression, decreased libido, ovarian cysts, oligomenorrhea, and amenorrhea 5

Protection Against Complications

Levonorgestrel IUDs provide protection against:

• Ectopic pregnancy (rate 0.02 per 100 woman-years) 2
• Pelvic inflammatory disease 2
• Iron deficiency (by reducing menstrual blood loss) 2

All IUDs: Small risk of pelvic infection exists only during first 21 days after insertion 1