BACKGROUND AND PURPOSE:

• Currently, clinicians only offer copper intrauterine devices (IUDs) for emergency contraception
• Guidelines recommend oral emergency contraception for women with a levonorgestrel IUD who have had recent, unprotected intercourse
• Turok et al. (NEJM, 2021) assessed the 1 month pregnancy risk with the levonorgestrel IUD vs copper IUD for emergency contraception

METHODS:

• Multicenter, randomized, participant-blind, noninferiority trial
• Participants
  • Women who sought emergency contraception after at least one episode of unprotected intercourse within the 5 days before presentation and agreed to placement of an IUD
• Intervention
  • Levonorgestrel 52-mg IUD
  • Copper T380A IUD
• Primary outcome
  • Positive urine pregnancy test 1-month after IUD insertion
    • If unavailable, pregnancy status was determined using survey and health record data
  • Non-inferiority margin was calculated at 2.5 percentage points

RESULTS:

• Levonorgestrel IUD: 317 women | Copper IUD: 321 women
• 1-month pregnancy tests obtained in 92.5% of participants
  • Levonorgestrel IUD: 290
  • Copper IUD: 300
• Pregnancy rates
  • Levonorgestrel IUD: 0.3% (95% CI, 0.01 to 1.7)
  • Copper IUD: 0% (95% CI, 0 to 1.1)
• The levonorgestrel IUD was noninferior to the copper IUD at preventing pregnancy
  • Between-group absolute difference in both analyses: 0.3 percentage points (95% CI, −0.9 to 1.8)
  • Result was the same for intention to treat and per-protocol analyses
• Adverse events that resulted in participants seeking medical care in the first month after IUD placement
  • Levonorgestrel IUD: 5.2% of participants
  • Copper IUD: 4.9% of participants
  • Absolute risk difference in total events between the groups: −0.2 (95% CI, −3.6 to 3.3)

CONCLUSION:

• The levonorgestrel IUD was noninferior to the copper IUD for emergency contraception
• In addition, the authors state

Unlike the case with oral levonorgestrel, the efficacy of the levonorgestrel IUD for emergency contraception does not appear to be affected by higher body-mass index

Since the IUD also provides ongoing contraception, it avoids the delayed initiation of ongoing contraception that is recommended when ulipristal acetate is used for emergency contraception 

Learn More – Primary Sources:

Levonorgestrel vs. Copper Intrauterine Devices for Emergency Contraception

Related ObG Topics:

Emergency Contraception: What, When and How?

Emergency Contraception: What’s your Best Option?

Expert Opinion: Over-the-Counter Contraceptives for Adolescents

Can Copper and Levonorgestrel IUD Use Be Safely Extended?