Benefits and Risks of Emergency Contraception
Emergency contraception (EC), including pills like levonorgestrel or ulipristal acetate and copper IUDs, provides a critical option to prevent pregnancy after unprotected sex or contraceptive failure.
How EC Works & Effectiveness
- Hormonal EC delays or inhibits ovulation—not an abortifacient—and does not affect existing pregnancies. Copper IUD works by interfering with sperm to egg interaction. ([turn0search26]turn0search2]turn0search1])
- Ulipristal acetate reduces pregnancy risk by ~85% if taken within 120 hrs. Levonorgestrel pills are ~75–89% effective within 72 hrs. Copper IUD is the most effective (~ 99% efficacy), regardless of weight. ([turn0search1]turn0search30]turn0search27])
- Effectiveness decreases over time—earlier administration leads to better results. ([turn0search1]turn0search2])
Major Benefits
- A readily available safeguard after contraceptive failure or unprotected sex. ([turn0search3]turn0search6])
- Copper IUD doubles as long‑term contraception for up to 10–12 years. ([turn0search27]turn0search1])
- Safe for nearly all users with no long-term risk to fertility. ([turn0search0]turn0search8])
Possible Side Effects & Risks
- Common side effects include nausea (~23%), abdominal pain (~18%), fatigue or headache (~17%), and vomiting (~6%). Usually resolve within 24 hours. ([turn0search4]turn0search14])
- Temporary menstrual changes such as spotting or cycle delay may occur. ([turn0search26]turn0search14])
- Levonorgestrel's effectiveness may decline in users with higher BMI; ulipristal performs slightly better, but copper IUD is unaffected by weight. ([turn0search16]turn0news22]turn0search27])
Safety Profile & Clinical Considerations
- WHO, ACOG, and AAFP confirm EC is safe and benefits significantly outweigh minimal risks. No serious medical contraindications exist. ([turn0search8]turn0search1]turn0search6])
- No impact on future fertility or a developing pregnancy. ([turn0search0]turn0search29])
- Drug interactions—e.g., with rifampicin, St John’s wort—may reduce effectiveness. Vomiting within 2 hours of ingestion warrants repeat dosing. ([turn0search26]turn0search10]turn0news22])
Limitations & Public Health Impact
- Widespread availability has not consistently lowered population-level unintended pregnancy rates. Advance provision doesn't guarantee use when needed. ([turn0search2]turn0search1])
Usage Guidelines
- Levonorgestrel available OTC; ulipristal requires prescription in most settings. Copper IUD insertion requires clinical provider. ([turn0news22]turn0search27])
- Use EC as soon as possible—ideally within 24 hours. Levonorgestrel ≤72 hrs; ulipristal ≤120 hrs; copper IUD ≤5 days. ([turn0search5]turn0search1]turn0search27])
- Copper IUD is preferred for those with high BMI or taking enzyme-inducing meds or those seeking longer-term contraception. ([turn0search16]turn0search27])
- If vomiting occurs <2 hours post-dose, a repeat dose is advised. ([turn0search4]turn0search10])
Quick Reference Table
| Option | Window | Effectiveness | Main Considerations |
|---|---|---|---|
| Levonorgestrel pills | ≤ 72 hrs | ≈ 75–89% | Less effective in higher BMI; mild side effects |
| Ulipristal acetate (Ella) | ≤ 120 hrs | ≈ 85% | Prescription required; better efficacy in higher BMI |
| Copper IUD | ≤ 5 days | ≈ 99% | Requires insertion; menstrual changes, longest protection |
Conclusion
Emergency contraception offers a safe, effective option to prevent unintended pregnancy when used promptly and appropriately. Choice between pills and IUD should be guided by timing, BMI, access, and future contraceptive needs. While EC isn’t a substitute for routine birth control, it is an essential option for individual protection. For personalized advice, consult a healthcare provider.