Emergency Contraceptive Pills: Effective Within 72 Hours After Intercourse? - Obstetrics and Gynecology

More Info

---

Emergency contraceptive pills (ECPs) are a crucial option for preventing unintended pregnancies after unprotected intercourse or contraceptive failure, such as a broken condom. The effectiveness of these pills is time-sensitive, and understanding the nuances of their use is essential for anyone considering them.

To address your question directly: Yes, emergency contraceptive pills can be effective if taken within 72 hours (3 days) after unprotected intercourse. However, the sooner you take them, the more effective they are. Research indicates that ECPs, particularly those containing levonorgestrel (like Plan B), are most effective when taken within 24 hours of unprotected sex, with efficacy decreasing as time passes. Studies suggest that taking levonorgestrel within 72 hours can reduce the risk of pregnancy by approximately 75-89%, depending on how soon after intercourse the pill is taken.

There are two main types of emergency contraceptive pills available: levonorgestrel (Plan B One-Step and its generics) and ulipristal acetate (Ella). While both are effective, ulipristal acetate can be taken up to 120 hours (5 days) after unprotected intercourse, and it maintains its efficacy better than levonorgestrel as time progresses. This means that if you are beyond the 72-hour mark but within 120 hours, ulipristal acetate is a viable option.

It's important to note that ECPs are not intended for regular contraceptive use and should only be used in emergencies. They do not terminate an existing pregnancy and are not effective if taken after implantation has occurred. Additionally, ECPs do not provide protection against sexually transmitted infections (STIs).

When considering the use of ECPs, it’s also essential to be aware of potential side effects. Common side effects include nausea, fatigue, headache, dizziness, breast tenderness, and changes in menstrual bleeding. While these side effects can be uncomfortable, they are generally short-lived. If you experience severe side effects or if your period is more than a week late after taking the pill, it’s advisable to take a pregnancy test and consult a healthcare provider.

In summary, if you have had unprotected intercourse, taking an emergency contraceptive pill within 72 hours is effective, with the highest efficacy occurring when taken as soon as possible. If you are beyond that window, ulipristal acetate remains an option up to 120 hours post-intercourse. Always consult with a healthcare professional for personalized advice and to discuss any concerns regarding contraceptive methods and their interactions with other medications.