A 28-year-old woman presents to the emergency department 18 hours after unprotected intercourse with her boyfriend. She has a regular 28-day menstrual cycle and is currently on day 14 of her cycle. She is otherwise healthy with no contraindications to any form of emergency contraception. Her last menstrual period was 14 days ago. She is anxious about the possibility of pregnancy and wants the most effective option available. What is the most appropriate emergency contraceptive regimen for this patient?

Explanation

## Emergency Contraception: Most Effective Option **Key Point:** The copper intrauterine device (Cu-IUD) is the **most effective** form of emergency contraception available, with a failure rate of less than 0.1% (>99% efficacy), and can be inserted up to **5 days (120 hours)** after unprotected intercourse. ### Mechanism of Action The copper IUD works as emergency contraception by: 1. **Copper ion toxicity** to sperm — impairs sperm motility and fertilization 2. **Endometrial changes** — creates a hostile environment for implantation 3. **Effective regardless of cycle phase** — works even in the periovulatory period ### Comparative Efficacy of Emergency Contraceptives | Emergency Contraceptive | Window | Efficacy | Notes | |---|---|---|---| | **Copper IUD** | ≤5 days | **>99%** | Gold standard; most effective overall | | **Ulipristal acetate** | ≤120 hours | ~85–95% | Not approved/widely available in India | | **Mifepristone 10 mg** | ≤72 hours | ~85–90% | Not available as EC in India | | **Levonorgestrel 1.5 mg** | ≤72 hours | 60–85% | OTC; efficacy reduced near ovulation | **High-Yield (NEET PG / Indian Context):** This patient is on **day 14 of a 28-day cycle** — the periovulatory phase — presenting **18 hours** after unprotected intercourse. She is at peak fertility risk. In Indian clinical practice (per **FOGSI/ICOG guidelines**), the **copper IUD** is the recommended most effective emergency contraceptive. Ulipristal acetate is **not approved or widely available in India**, making it an inappropriate "most effective" choice in the Indian NEET PG context. **Clinical Pearl:** The copper IUD not only provides the highest efficacy as emergency contraception but also offers **ongoing long-term contraception** (up to 10 years), making it the preferred choice when the patient has no contraindications and the device is available. In the ED setting in India, IUD insertion is a feasible and recommended procedure. **Why other options are incorrect:** - **Option B (Ulipristal acetate):** Not approved/available in India; even globally, it is less effective than the copper IUD. - **Option C (Mifepristone 10 mg):** Not available as an emergency contraceptive in India. - **Option D (Levonorgestrel 1.5 mg):** Least effective of the options listed; efficacy is further reduced in the periovulatory phase. [cite: FOGSI Good Clinical Practice Recommendations on Emergency Contraception; Park's Textbook of Preventive and Social Medicine, 26e Ch 15]