What is the most effective emergency contraception (EC) kit?

From the Guidelines

The most effective emergency contraception option is the copper intrauterine device (IUD), which can be inserted up to 5 days after unprotected sex and is over 99% effective. For oral options, ulipristal acetate (ella) is more effective than levonorgestrel, especially for women weighing over 165 pounds, and works up to 5 days after unprotected sex 1. Levonorgestrel (Plan B One-Step, Take Action) is widely available over-the-counter without age restrictions and should be taken as soon as possible within 72 hours of unprotected sex.

Key Points to Consider

• The copper IUD is the most effective emergency contraception method, with a failure rate of less than 1% 2.
• Ulipristal acetate may be more effective than levonorgestrel formulations after the first 72 hours and for women who are overweight or obese 1.
• Levonorgestrel is less effective than ulipristal acetate for women weighing over 165 pounds 2.
• Emergency contraception works primarily by delaying ovulation to prevent fertilization, not by affecting an already implanted pregnancy.
• Side effects may include nausea, headache, fatigue, and irregular bleeding.
• It's essential to follow up with regular contraception after using emergency methods, as they only protect against the single instance of unprotected sex.

Comparison of Options

• Copper IUD: over 99% effective, can be inserted up to 5 days after unprotected sex
• Ulipristal acetate (ella): more effective than levonorgestrel, especially for women weighing over 165 pounds, works up to 5 days after unprotected sex
• Levonorgestrel (Plan B One-Step, Take Action): widely available over-the-counter, should be taken as soon as possible within 72 hours of unprotected sex
• Combined estrogen and progestin regimen: less effective than UPA or levonorgestrel and associated with more frequent side effects 3.

From the FDA Drug Label

The primary efficacy analyses were performed on subjects less than 36 years of age who had a known pregnancy status after taking study medication Table 3: Summary of Clinical Trial Results for Women Who Received a Single Dose of ella (30 mg Ulipristal Acetate) Open-Label Study 48 to 120 Hours Single-Blind Comparative Study 0 to 72 Hours N = 1,242 N = 844 Expected Pregnancy Rate 5.5 5.6 Observed Pregnancy Rate (95% confidence interval) 2.2 (1.5, 3.2) 1.9 (1.1, 3. 1)

The best emergency contraception kit is ella (ulipristal acetate), as it has been shown to be effective in reducing pregnancy rates when taken within 120 hours of unprotected intercourse.

• Key benefits: + Effective in reducing pregnancy rates + Can be taken up to 120 hours after unprotected intercourse + Available by prescription
• Important considerations: + Should not be used as a regular form of birth control + May not be suitable for women with certain medical conditions or taking certain medications + Should be used in conjunction with a reliable barrier method of contraception until the next menstrual period 4 5 6

From the Research

Emergency Contraception Options

• There are several emergency contraception options available, including levonorgestrel (LNG), ulipristal acetate (UPA), and the copper intrauterine device (IUD) 7, 8.
• UPA is a selective progesterone receptor modulator that can be taken within 120 hours of unprotected intercourse or failed contraception 9.
• LNG is available over the counter for women of all ages, while UPA requires a provider's prescription 8.

Efficacy of Emergency Contraception

• UPA has been shown to be more effective than LNG in preventing pregnancy, especially when taken later than 72 hours postcoitus 8, 10.
• The copper IUD is the most effective method of emergency contraception, with a success rate of over 95% 7, 8.
• A study comparing UPA and LNG found that UPA resulted in 720 fewer unintended pregnancies, 736 fewer abortions, and 80 fewer deliveries 11.

Factors Affecting Efficacy

• Women who weigh more than 75 kg or have a body mass index greater than 25 kg/m2 may have a higher risk of unintended pregnancy when using oral LNG EC 8.
• UPA may be a better option for these women, as it has been shown to be effective regardless of body mass index or an adverse interaction of combined oral contraceptives (COCs) on UPA efficacy 11.

Cost-Effectiveness

• A cost-effectiveness analysis found that UPA was the dominant choice of oral emergency contraception among COC users with a prolonged "missed" pill episode, resulting in cost savings and additional quality-adjusted life-years 11.