Emergency Contraceptive Pills: Usage and Effectiveness

Regarding emergency contraceptive pills?

Is it true that oral contraceptives should be started on the first day of menstruation and taken for seven days to be effective, or can they be started at any time as long as they are taken continuously for seven days to be effective? Is the Yaz oral contraceptive effective? Are there any precautions to consider when taking oral contraceptives? Thank you!

Jie, 10~19 year old female. Ask Date: 2009/12/16

Dr. Dong Yuhong reply Obstetrics and Gynecology

Hello, if you choose to use birth control pills for contraception, it is essential to take them on time.
The starting time for taking the medication is indicated in the product instructions.
YAZ is a low-dose estrogen contraceptive pill, which is less likely to cause some common side effects associated with high-dose estrogen contraceptives.
However, if you do not take it on time or miss a dose, it is advisable to use condoms during sexual intercourse to prevent unintended pregnancy.
It might be beneficial to delay sexual activity for a few years, as this could reduce a lot of worries and stress.
Thank you.

Reply Date: 2009/12/16

More Info

Emergency contraceptive pills (ECPs) are a crucial option for preventing unintended pregnancies after unprotected intercourse or contraceptive failure. Understanding their usage and effectiveness is essential for anyone considering them.

Usage of Emergency Contraceptive Pills
ECPs, often referred to as "morning-after pills," are designed to be taken after unprotected sex. There are two main types of ECPs: those containing levonorgestrel (Plan B One-Step) and those containing ulipristal acetate (ella). The effectiveness of these pills is highest when taken as soon as possible after unprotected intercourse, ideally within 72 hours for levonorgestrel and up to 120 hours for ulipristal acetate.

Regarding your question about starting regular contraceptive pills (often referred to as birth control pills) and their effectiveness, it is important to clarify the following:
1. Starting Birth Control Pills: If you begin taking a combined oral contraceptive (COC) pill, it is generally recommended to start taking them at least seven days before relying on them for contraception. If you start taking the pill during your menstrual cycle, it may take up to seven days for the contraceptive effect to kick in. However, if you start taking the pill during the first five days of your menstrual cycle, you are protected from pregnancy immediately.

2. Continuous Use: If you take the pill continuously for seven days, regardless of when you start, you will achieve contraceptive effectiveness. However, it is crucial to take the pills consistently at the same time every day to maintain their effectiveness.

Effectiveness of Emergency Contraceptive Pills
ECPs are not as effective as regular contraceptive methods. The sooner you take them after unprotected intercourse, the more effective they will be. Studies show that levonorgestrel can reduce the risk of pregnancy by 75-89% when taken within 72 hours. Ulipristal acetate is more effective than levonorgestrel, especially closer to the time of ovulation.

Safety and Considerations
1. Side Effects: Common side effects of ECPs include nausea, fatigue, headache, dizziness, breast tenderness, and changes in your menstrual cycle. Most side effects are mild and resolve quickly.

2. Not for Regular Use: ECPs are intended for occasional use and should not replace regular contraceptive methods. They are not as effective as regular birth control pills and should not be used as a primary form of contraception.

3. Consultation: It is advisable to consult with a healthcare provider before starting any contraceptive method, including ECPs. They can provide personalized advice based on your health history and lifestyle.

4. Menstrual Cycle Changes: After taking ECPs, your next period may be earlier, later, or heavier than usual. If your period is more than a week late, consider taking a pregnancy test.

Conclusion
In summary, emergency contraceptive pills are a vital option for preventing unintended pregnancies after unprotected intercourse. If you are considering starting regular birth control pills, remember that they require a consistent regimen to be effective. Always consult with a healthcare provider for personalized advice and to discuss the best contraceptive options for your needs.

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