Reproductive · Year 2 · from Reproductive
Case 3: Emergency Contraception
Clinical Image
Source: Wikipedia - Emergency contraception - CC BY-SA 4.0
Case Presentation
A 24-year-old woman presents to the clinic 36 hours after unprotected intercourse. The condom broke during sex, and she is not using any other contraception. Her last menstrual period was 12 days ago, and she has regular 28-day cycles. She is concerned about pregnancy and requests emergency contraception. Her BMI is 32. Physical examination is unremarkable. A urine pregnancy test is negative. The provider discusses emergency contraception options. Given that she is likely in her fertile window (around day 12-14 of her cycle) and her elevated BMI may reduce levonorgestrel effectiveness, the copper IUD is recommended as the most effective option. The copper IUD is effective as emergency contraception for up to 5 days after unprotected intercourse and is the most effective method regardless of BMI, with a pregnancy rate of less than 0.1%. Additionally, it provides ongoing highly effective contraception. The patient agrees. A copper IUD is inserted the same day. She is counseled that her next period may be heavier than usual. At follow-up, she confirms she had a normal menstrual period and the IUD is in good position. She decides to continue using the copper IUD for ongoing contraception.
Key Learning Points
- The copper IUD is the most effective form of emergency contraception (pregnancy rate <0.1%) and can be inserted up to 5 days after unprotected intercourse or 5 days after expected ovulation
- Levonorgestrel EC (Plan B) is most effective within 72 hours but has reduced efficacy in women with BMI >25-30 kg/m2; ulipristal acetate maintains efficacy at higher weights
- Emergency contraception works primarily by delaying or inhibiting ovulation; it does not disrupt an established pregnancy
- The copper IUD provides the added benefit of ongoing highly effective contraception for up to 10 years