Emergency Contraceptive Pills: Effectiveness After Unprotected Intercourse - Obstetrics and Gynecology

More Info

---

Emergency contraceptive pills (ECPs), commonly referred to as "morning-after pills," are designed to prevent pregnancy after unprotected intercourse. The effectiveness of these pills largely depends on the timing of ingestion relative to the unprotected sexual activity.
When taken as directed, ECPs can significantly reduce the risk of pregnancy. The two most common types of ECPs are those containing levonorgestrel (Plan B One-Step and others) and ulipristal acetate (ella). Levonorgestrel is most effective when taken within 72 hours after unprotected intercourse, while ulipristal acetate can be effective up to 120 hours after. However, both types are more effective the sooner they are taken after the incident.

In your case, if you took the emergency contraceptive pill in the morning and then had unprotected intercourse in the afternoon, the timing is crucial. If the ECP was taken within the appropriate window (ideally as soon as possible after the unprotected intercourse), it should still provide a level of protection against pregnancy. However, it is important to note that ECPs are not 100% effective. Studies suggest that they can reduce the risk of pregnancy by up to 89% when taken within 72 hours, but their effectiveness diminishes the longer you wait after the unprotected intercourse.

Additionally, factors such as where you are in your menstrual cycle can influence the likelihood of pregnancy. If you are close to ovulation, the chances of becoming pregnant may be higher, as the ECPs work primarily by delaying ovulation. If ovulation has already occurred, the effectiveness of ECPs is significantly reduced.

It is also important to consider that ECPs do not terminate an existing pregnancy; they work primarily to prevent ovulation or fertilization. If you are concerned about the possibility of being pregnant after taking ECPs and having unprotected intercourse, it is advisable to take a pregnancy test if your next period is late or if you experience any unusual symptoms.

In summary, while taking an emergency contraceptive pill in the morning and then having unprotected intercourse in the afternoon does carry some risk of pregnancy, the ECP should still provide a level of protection. However, it is not foolproof, and if you have concerns about potential pregnancy, monitoring your menstrual cycle and considering a pregnancy test is recommended. Always consult with a healthcare provider for personalized advice and to discuss any further concerns regarding contraceptive methods and sexual health.