Emergency contraception

Emergency contraception is treatment used after sex to reduce the chance of pregnancy. You may need it if no contraception was used or if your usual method failed, such as a condom breaking or missed birth control pills.

Treatment should be used as soon as possible. Depending on the method, it may be used within five days after sex.

The main options are:

• An emergency contraceptive pill containing levonorgestrel
• An emergency contraceptive pill containing ulipristal acetate
• A copper intrauterine device, or IUD, placed inside the uterus

Emergency contraception mainly works by preventing or delaying ovulation, when an egg is released. A copper IUD also interferes with fertilization. These treatments do not end an established pregnancy and are not abortion medicines.

Emergency contraception does not protect against sexually transmitted infections, or STIs.

Emergency contraception may be offered after:

• Sex without contraception
• A condom breaking, slipping or being used incorrectly
• Missed or late hormonal contraception
• A contraceptive injection being given late
• A diaphragm or cervical cap moving out of place
• Sexual assault when pregnancy is possible

It may also be considered when there is uncertainty about whether a regular contraceptive method was used correctly.

The choice depends on how long it has been since sex, your medications, your preferences and whether you want ongoing contraception. Body weight may also affect how well oral emergency contraception works, particularly levonorgestrel. A copper IUD remains highly effective across body weights.

Emergency contraception may be suitable if pregnancy is possible and sex occurred within the treatment window. Because timing matters, seek treatment promptly rather than waiting for your next period.

Emergency contraceptive pills are not useful for an established pregnancy. However, available evidence does not show that taking one accidentally harms an existing pregnancy.

Some medicines and herbal products can reduce the effectiveness of emergency contraceptive pills. These include certain treatments for epilepsy, tuberculosis or HIV, and St John’s wort. A copper IUD may be a better option in this situation.

A copper IUD should not be inserted if you are pregnant. It may also be unsuitable or need to be delayed if you have:

• A current pelvic infection or untreated gonorrhea or chlamydia
• Unexplained vaginal bleeding that needs assessment
• A uterus whose shape prevents correct IUD placement
• A copper allergy or Wilson disease, which causes copper buildup

Tell the clinician if you have pelvic pain, fever, unusual discharge, an allergy to any product involved, or a history of difficult IUD insertion. This does not always rule out an IUD, but it may affect the assessment.

If more than five days have passed, oral emergency contraception may no longer be appropriate. In some circumstances, a clinician can still consider a copper IUD based on the likely timing of ovulation.

The treating facility’s own instructions take priority over general information in this article.

No fasting or bowel preparation is needed. If possible, be ready to provide:

• The dates of unprotected sex
• The first day of your last period
• Your usual cycle pattern
• Details of missed contraception
• A list of medicines, supplements and allergies

A pregnancy test may be performed, particularly before IUD placement. However, a test taken soon after sex cannot detect a pregnancy from that recent event.

For IUD placement, you may be offered STI testing and pain relief. Ask whether you should take a usual over-the-counter pain medicine beforehand. Do not take ulipristal and levonorgestrel together unless specifically directed, because they may interfere with each other.

For oral emergency contraception, you swallow a tablet as soon as possible. Ulipristal can be used within five days after sex. Levonorgestrel works best within three days, although it may provide some benefit later within the five-day window.

If you vomit soon after taking the tablet, contact a pharmacist or healthcare professional. You may need another dose.

For copper IUD placement, you lie on an examination table. A clinician places a speculum in the vagina, similar to during a cervical screening test. The cervix is cleaned, and a thin instrument may be used to measure the uterus.

The folded IUD is passed through the cervix into the uterus using a narrow tube. The tube is removed, leaving the IUD in place. Two soft threads extend a short distance through the cervix into the vagina.

Placement usually takes several minutes. You may feel strong cramping during insertion. The copper IUD begins working immediately and can remain in place as ongoing contraception if you want it.

Emergency contraceptive pills do not cause procedure-related pain, although temporary cramps, headache, nausea, tiredness or breast tenderness can occur. IUD placement may cause cramps for several hours, followed by milder cramping or spotting.

You can eat and drink normally.

Most people can return to usual activities as soon as they feel comfortable. Oral emergency contraception does not protect you from pregnancy if you have unprotected sex again later in the same cycle.

Driving is usually allowed after either treatment. Arrange help if you feel faint after IUD placement or if you were given a sedating medicine, which is uncommon.

Most people can return to work the same day. You may prefer lighter plans after IUD placement if you have cramps.

After levonorgestrel, regular hormonal contraception can generally be started or restarted immediately. After ulipristal, wait five days before restarting a hormonal method because it could reduce ulipristal’s effect. Use condoms or avoid sex until your regular method has become effective. Follow the specific instructions supplied with your treatment.

Your next period may come earlier or later than expected and may be lighter or heavier. A copper IUD can make periods heavier, longer or more painful, especially during the first few months.

Emergency contraception can fail, especially when treatment is delayed or another episode of unprotected sex occurs afterward.

Pills may cause nausea, headache, abdominal discomfort, tiredness and changes to the next period. Serious reactions are uncommon, but seek help for swelling, breathing difficulty or another possible allergic reaction.

Risks from copper IUD placement include:

• The IUD coming partly or completely out
• Infection around the time of insertion, particularly with an untreated STI
• Perforation, meaning the IUD passes through the uterine wall
• Pain, bleeding or difficulty with placement

Pregnancy with an IUD in place is uncommon. If it happens, prompt assessment is needed to check the pregnancy’s location and discuss the IUD.

There is no immediate test showing whether emergency contraception worked. Take a home pregnancy test about three weeks after treatment. Test sooner if your period is more than a week late or is much lighter than usual.

Routine follow-up is generally not needed after an emergency contraceptive pill if you feel well and the pregnancy test is negative.

After IUD placement, follow the clinic’s instructions. A routine check is not always required, but contact the clinic if you cannot feel the threads, feel hard plastic at the cervix, or think the IUD has moved.

Consider STI testing if sex occurred without a condom. Emergency contraception does not prevent or treat an infection.

The available methods involve different trade-offs.

Ulipristal is generally more effective than levonorgestrel later in the five-day treatment window. However, you must wait five days before restarting hormonal contraception, and some medicines reduce its effectiveness.

Levonorgestrel is often easier to obtain and allows you to restart regular hormonal contraception immediately. It becomes less effective with time and may be less effective at higher body weights.

A copper IUD is the most effective emergency option and provides ongoing contraception. It requires a pelvic procedure, may cause more cramping or bleeding, and is not suitable for everyone.

Choosing no emergency treatment avoids medication and IUD placement, but it leaves the pregnancy risk unchanged. Regular contraception started now can prevent future pregnancies but cannot reliably prevent pregnancy from sex that has already occurred.

Abortion is not emergency contraception. It is a separate option only after a pregnancy has begun.

Contact your healthcare team promptly if:

• You vomit soon after taking an emergency contraceptive pill
• Your period is more than one week late
• A pregnancy test is positive or unclear
• Pain or bleeding after IUD placement is worsening rather than improving
• You develop fever, chills or unusual vaginal discharge
• You cannot feel the IUD threads or think the IUD has come out

Seek urgent or emergency care for severe or one-sided lower abdominal pain, fainting, shoulder-tip pain, difficulty breathing, or bleeding that rapidly soaks pads or causes weakness. These symptoms need prompt assessment, especially with a positive pregnancy test or an IUD in place.

Will I be asleep?

No. Taking a pill requires no anaesthesia. Copper IUD placement is usually done while you are awake. Local pain relief may be available.

Can I drive home?

Usually, yes. Do not drive if you feel faint or were given a sedating medicine.

How painful is it?

The pills are painless to take but may cause temporary cramps or nausea. IUD insertion can cause brief, strong cramping, followed by milder cramps.

When will I know if it worked?

You cannot know immediately. Take a pregnancy test about three weeks after treatment, or sooner if your period is more than one week late.

Will emergency contraception cause an abortion?

No. Emergency contraception prevents pregnancy before it becomes established. It does not end an existing pregnancy.

Can I have sex again afterward?

You can, but oral emergency contraception does not protect against later sex. Use condoms or avoid sex until your ongoing contraceptive method is effective.