Emergency Contraception: Your Options After Unprotected Sex

In short: Emergency contraception is used after intercourse without effective protection. There are three types: levonorgestrel tablets within 72 hours, ulipristal tablets up to 5 days, and the copper IUD within 5 days, which is more than 99% effective. Side effects are minor, such as nausea and a change in the timing of the period. It prevents pregnancy and does not affect a pregnancy that has already started.

Emergency contraception refers to the methods used to help prevent pregnancy after unprotected sexual intercourse. If you’re worried about a recent contraceptive slip-up, understanding your options quickly can make a real difference.

Unprotected sexual intercourse can happen after:

• missing birth control pills
• or by a broken condom
• sexual assault: Sometimes emergency contraception is needed in cases where the woman has been raped to prevent an unwanted pregnancy.
• no contraception used intentionally
• incorrect use of contraception

These methods are usually referred to as the (morning-after method).

Emergency contraceptive methods:

• Levonorgestrel pills:
• Should be taken within 72 hours after intercourse
• Between 72 and 96 hours it may still work but is much less effective, and after 96 hours it does not work; ulipristal or a copper IUD should be used instead
• It is over the counter in some countries but in others it needs a prescription
• It works by delaying ovulation; it does not work if ovulation has already happened
• Side effects:
• nausea
• breast pain
• fatigue
• menstrual changes
• Ulipristal acetate pill:
• Can be used up to 5 days after intercourse
• More effective closer to ovulation
• Needs a prescription in some countries but is available from pharmacies in others; after taking it, wait 5 days before starting or restarting hormonal contraception, and use condoms in the meantime
• Delays ovulation even if it was about to occur
• Copper intrauterine device:
• The most effective of all methods
• It has to be inserted within 5 days of intercourse, or within 5 days of the earliest expected date of ovulation
• More than 99% effective
• Provides long term contraception up to 10 years
• Copper is toxic to sperms and also it prevents fertilization and embryo implantation

To understand the process these methods act on, you can read our article on how fertilization happens.

Does emergency contraception terminate an existing pregnancy?

No

Does emergency contraception protect against sexually transmitted diseases?

No

What is the success rate of different emergency contraception methods?

• Levonorgestrel pills: about 1-3 in 100 women still become pregnant, and it works best the earlier it is taken
• Ulipristal acetate pill: about 1-2 in 100 women still become pregnant; it is more effective than levonorgestrel
• Copper intrauterine device: more than 99% effective

The following factors affect how well emergency contraception work:

• Time since intercourse
• Timing of ovulation
• BMI (levonorgestrel is less effective if BMI is over 26 or weight over 70 kg; a copper IUD, ulipristal, or a double dose of levonorgestrel is advised)
• Drug interactions like enzyme inducing drugs

After emergency contraception, do a pregnancy test 3 weeks later if your next period is late, lighter than usual or unusual, and consider testing for sexually transmitted infections.

If you think you may need emergency contraception, it’s best to act quickly and speak with a gynaecologist who can help you choose the most suitable option for your situation. Dr Najeeb Layyous and his clinical team are available to guide you through your choices with care and confidentiality.

Dr Najeeb Layyous F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist