Guideline Recommendations for Emergency Contraception after Low‑Risk Intercourse
Indications and General Practice
- The Centers for Disease Control and Prevention (CDC) recommends offering emergency contraception (EC) to any patient requesting it after intercourse, even when the pregnancy risk is perceived to be low (e.g., condom use without ejaculation). 1
- The CDC emphasizes that EC should not be withheld solely because the patient used a condom, as patient autonomy and anxiety justify provision of EC. 1
First‑Line Oral Emergency Contraception: Levonorgestrel 1.5 mg
- The American Academy of Pediatrics (AAP) and CDC consider a single 1.5 mg dose of levonorgestrel (or two 0.75 mg tablets taken together) the most appropriate option for patients presenting within hours of intercourse. [2][1]
- Levonorgestrel should be taken as soon as possible; maximum effectiveness is achieved when administered within 72 hours, with efficacy declining markedly after this period. 1
- The medication remains usable up to 120 hours (5 days) after intercourse, although effectiveness is reduced when taken at 96–120 hours. 1
Alternative Oral Emergency Contraception: Ulipristal Acetate (UPA) 30 mg
- The CDC states that ulipristal acetate 30 mg is more effective than levonorgestrel for EC when taken between 72 hours and 120 hours after intercourse. 1
- A single 30 mg dose of UPA is recommended. 1
- After UPA use, patients should start regular contraception immediately and must use a barrier method or abstain for 14 days (or until the next menstrual period, whichever occurs first). 1
- A pregnancy test is advised if no withdrawal bleed occurs within 3 weeks after UPA administration. 1
Most Effective Emergency Contraception: Copper Intrauterine Device (IUD)
- The CDC identifies the copper IUD as the most effective EC method, with a failure rate of less than 1 %. 1
- The IUD can be inserted within 5 days of intercourse (or up to 5 days after ovulation if the timing of ovulation is known). 1
- In addition to EC, the copper IUD provides ongoing long‑term contraception after insertion. 1
Post‑EC Management
- After levonorgestrel use, patients may resume or initiate regular contraception immediately; a pregnancy test should be performed if menstrual bleeding is delayed by more than 1 week. 1
Special Populations
- The CDC indicates that prior use of combined hormonal contraceptives (e.g., cyproterone acetate/ethinyl estradiol) does not contraindicate the provision of EC; it may be given regardless of previous hormonal contraceptive use. 1
Counseling Points on Pregnancy Risk
- Condom use without ejaculation carries a very low pregnancy risk, but the CDC notes that pre‑ejaculate can theoretically contain sperm, albeit with minimal risk. 1
- Clinicians should counsel patients that EC efficacy diminishes with time, reinforcing the importance of prompt administration. 1
- When UPA is selected, clinicians must specifically remind patients of the 14‑day barrier method requirement. 1
Emergency Contraception Guidelines
Standard Levonorgestrel Dosing
- The American Academy of Pediatrics recommends a standard dose of 1.5 mg levonorgestrel as a single dose for emergency contraception, which can be given as one 1.5 mg pill or two 0.75 mg pills 3, 4
- The Centers for Disease Control and Prevention (CDC) suggests that levonorgestrel effectiveness decreases significantly after 72 hours, with pregnancy rates increasing at 4-5 days post-intercourse, highlighting the importance of timely administration 5, 6
Why Not Higher Doses?
- The American College of Obstetricians and Gynecologists (ACOG) notes that levonorgestrel may be less effective in obese women regardless of dose, emphasizing the need for alternative methods in this population 5, 3
- The evidence suggests that the mechanism of action of levonorgestrel (delaying ovulation) has biological limits that cannot be overcome simply by increasing the dose, supporting the use of standard dosing 5, 3
When Levonorgestrel Is Insufficient
- The CDC recommends that for situations where levonorgestrel is suboptimal, such as beyond 72 hours (3-5 days post-intercourse), ulipristal acetate (UPA) 30 mg is significantly more effective, with 65% lower pregnancy risk in the first 24 hours and maintaining effectiveness throughout the full 120-hour window 5, 6
- The American Academy of Pediatrics suggests that for women weighing >165 pounds, UPA is more effective than levonorgestrel, highlighting the importance of considering patient weight in emergency contraception decisions 3, 6
- The CDC notes that for maximum efficacy at any timepoint within 5 days, the copper IUD is the most effective emergency contraception method with <1% failure rate, making it a highly effective option for women seeking emergency contraception 5, 3, 6
Clinical Algorithm
- The CDC recommends using a clinical algorithm that considers patient weight and time since intercourse to determine the most effective emergency contraception method, with levonorgestrel 1.5 mg single dose appropriate for women within 72 hours and of normal weight 5, 3
- The American Academy of Pediatrics suggests considering UPA 30 mg instead of levonorgestrel for women within 72 hours but weighing >165 lbs, and using UPA 30 mg as the preferred method between 72-120 hours 3, 6
- The CDC notes that copper IUD insertion within 5 days is an option for women seeking the highest efficacy, regardless of time since intercourse or patient weight 5, 6
Important Caveats
- The CDC recommends resuming regular contraception immediately after levonorgestrel use, but using a barrier method or abstaining for 7 days, and starting regular contraception immediately after UPA use but requiring a barrier method or abstinence for 14 days (or until next menses) 5, 6
- The American College of Obstetricians and Gynecologists (ACOG) emphasizes that emergency contraception should be taken as soon as possible within the appropriate window, as efficacy decreases with time for all oral methods 5
CDC Guideline Recommendations for Emergency Contraception: Ulipristal Acetate, Levonorgestrel, and Copper IUD
Efficacy by Timing
- Within 72 hours (0‑3 days) after unprotected intercourse, ulipristal acetate 30 mg and levonorgestrel 1.5 mg have comparable effectiveness, although emerging data suggest a modest advantage for ulipristal acetate even in this early window. (CDC) [7][8]
- Levonorgestrel achieves its highest effectiveness when taken within 72 hours, with low pregnancy rates when administered up to 4 days after intercourse. (CDC) 7
- When taken 3‑5 days (72‑120 hours) after intercourse, ulipristal acetate 30 mg remains significantly more effective than levonorgestrel, maintaining consistent efficacy throughout the full 120‑hour window. (CDC) [7][8]
- Levonorgestrel effectiveness declines sharply after 72 hours, with substantially higher pregnancy rates observed at 4‑5 days post‑intercourse. (CDC) 7
Body‑Mass Index (BMI) and Weight Considerations
- In women with obesity, levonorgestrel’s efficacy is reduced regardless of dose, making ulipristal acetate the preferred oral emergency contraceptive for this population. (CDC) [7][8]
Copper Intrauterine Device (IUD)
- The copper IUD can be inserted up to 5 days after unprotected intercourse (or up to 5 days after ovulation if the timing of ovulation is known), providing the highest efficacy among emergency‑contraception methods. (CDC) [7][8]
- After insertion, the copper IUD offers ongoing long‑term contraception, serving both as emergency and continuous birth control. (CDC) 7
Clinical Selection Algorithm
- For patients presenting within 72 hours and of normal weight (≤ 165 lb / 75 kg), either ulipristal acetate 30 mg or levonorgestrel 1.5 mg may be used, though ulipristal acetate may have a slight efficacy edge. (CDC) 7
- For patients presenting within 72 hours who weigh > 165 lb (≈ 75 kg), ulipristal acetate 30 mg is the preferred oral option. (CDC) citation not provided in the source; omitted per instructions.
- For patients presenting between 72‑120 hours after intercourse, ulipristal acetate 30 mg is the only oral emergency‑contraception option with proven effectiveness. (CDC) [7][8]